Search Results

Search found 1823 results on 73 pages for 'partitions'.

Page 60/73 | < Previous Page | 56 57 58 59 60 61 62 63 64 65 66 67  | Next Page >

• Any benefit of /home Ubuntu partition

  - by nightcrawler

  I want to have dual OS of Win8 & Ubuntu 12.10. Provided that Ubuntu can access ntfs partition of Windows but same can't be said about Windows this leads to a question mark on the significance of having /home partition while installing Ubuntu. As far as I know /swap & / are the two partitions directly used by Ubuntu to store programs, installation & stuff while the documents/media resides in /home. Now because Ubuntu releases are more frequent than Windows & updates needs backup & relate stuff, so I came to decision to not to use /home at all, rather keep all my documents/media in ntfs, which would be untouched while upgrading Ubuntu as Win updates are once in a decade! Is my thinking correct? If yes, what would be the minimum space I should allot to /home plus how much I should allot to / one must know that I plan to use heavy applications like Maple, Matlab & Sagemath on Ubuntu.

  Read the article

• How to fix GRUB on dualboot with Windows7 and Ubuntu?

  - by b_oliv

  I am a relatively recent user of Linux. I had several releases of Ubuntu installed on my laptop working in dual-boot and never had any issues. Recently, I installed openSUSE because I thought it would be necessary for an assignment at my university. It turns out it wasn't so I returned to Ubuntu and decided to burn the new .iso to a CD and install it. The problem is that during installation process I almost for sure messed up with the partitions and now, whenever I tried to load Windows 7, it will tells me that a required device is inaccessible. So, I reinstalled Ubuntu again and now all I get is that I am redirected to the GRUB menu without any warnings. I tried creating a Windows Recovery Disk but it gives me Unexpected I/O error. I suspect it is because it was downloaded from the Internet and maybe some files weren't there. I tried everything without success, so I decided to ask here, in the hope I can receive some help and also learn how to help others with it in the future. Here it is my boot info summary: http://paste.ubuntu.com/1344990/ Also, I might add, that on the boot-repair advanced options, the box repair Windows boot files is "locked", so I can't check it. EDIT: Apparentely, the box is locked, because, from what I understood after reading the boot-repair information, everything is fine with my windows boot-files... I still need some guidance though

  Read the article

• Win8 x64 Laptop (Samsung) unable to boot after installing Ubuntu

  - by user285872

  I posted here a while back and no one was able to help me so I am going to try to explain my problem better. I have a Samsung series 7 Ultrabook and I connected a USB optical drive with an Ubuntu 14.04 installation disc. I did not set or change any of my partitions, however, as I mainly wanted to just be able to boot from the disc and fool around with Ubuntu. Upon restarting my computer I get a blue-screen message saying: Recovery Your PC needs to be repiared The Boot configuration date file is missing some required information. File: \BCD Error Code: 0xc000000d You'll need to use the recovery tools on your installing media. If you don't have any installation media (like a disc or USB device), contact your system administrator or PC manufacturer. However I am never given the option to even try to boot to anything. When I turn my computer on the optical drive spins and then after a moment or two comes to a halt. I turned off safeboot and switched it to CSM (I believe that is what it is called) mode, and that makes it so when I turn my computer on it takes me to a Windows Recovery screen. I am able to change the date I want to recover and view all the applications installed, however upon recovering Windows says "All boot options are tried. Press key to recover with factory image using Recovery or any other keys for next boot loop iteration." It seems to be stuck in a loop. Can someone please help me?! I'm so confused and nothing is working!

  Read the article

• Black Screen after installing recommended Nvidia drivers. What to do?

  - by former_Windows_user

  New to Ubuntu. Problem description: Until recently I had Windows on my computer. My hard disk is divided into two partitions. On the first one (app. 10 GB) I had my Windows XP On the second one (app. 30 GB) I have some data I tried to install Ubuntu 12.04 on the first partition (the smaller one). Since I wanted to keep the data on my second partition, I chose the third install option. During the installation process I deleted the data on partition one, created a new partition with the same size, formatted it as ext4 and mounted / on it. The installation continued fine and at the end I restarted and took the CD out when it ejected automatically (it could have been also before the restart). Ubuntu started but I noticed that my computer was slow. Then a prompt appeared telling me that I did not have the optimal NVidia drivers and recommended to install a specific one. I clicked on the recommended driver, installation went apparently just fine and at the end I had to restart the system again. I did it, Ubuntu started, asked for my password, I typed it, pressed Enter, the screen turned black and remained like that (only the cursor was there and I could move it). I restarted and the same thing happened again. Has anyone had such a problem before and was able to solve it? With Windows I always installed drivers from CDs after installing Windows. Are the same CDs going to work for Ubuntu too or I should find special drivers? P.S. During the installation I was connected to the internet and I agreed on installing updates and the third party software. In the time before I installed that problematic but recommended NVidia driver I checked that there was between 6 and 7 GB free space on the first partition where I installed Ubuntu.

  Read the article

• Move entire OS from NTFS drive to bigger ext4 drive.

  - by pangel

  According to SMART data, the hard drive I curently use is about to fail. I bought a new, bigger drive to copy the system to a safer place. The old drive is 160GB. Ubuntu was installed with Wubi, and the partition is NTFS. There are a few other partitions around (recovery partition, swap...) that I don't care about. The new drive is 320GB. I would like the new system to run on ext4, not on NTFS. I looked at solutions that use dd, or clonezilla, but it seems that moving to a different filesystem prevents me from using them. I considered installing a brand new ubuntu on the new hard drive and then copy /home from the old drive to the new drive, but I heard that there would be file permission problems. I would also have to reinstall all my software. One last thing: the NTFS drive has dead sectors. I don't know how this can influence the copy process, but I mention it just in case. edit: I do not care about the windows partition. I just want Ubuntu to make the transition.

  Read the article

• Help! Problem dual boot ubuntu windows8 (can't start ubuntu) [duplicate]

  - by a35

  This question already has an answer here: Installing Ubuntu on a Pre-Installed Windows 8 (64-bit) System (UEFI Supported) 5 answers EDIT: I know that there are many topics about dual boot ubuntu windows8, i have read them, my problem is that i cant boot ubuntu neither from HDD nor from live USB. I know about boot repairing, but how can I use it, If i cant boot ubuntu?? I heard about terrible problems with windows 8-linux dual boot, but I really need ubuntu because of school. I read many tutorials how to install ubuntu next to windows8, but despite that a problem accured. Here is what I have done. I have MSI GE60, windows(64bit) is running on mSATA SSD C drive. HDD is divided to two partitions for windows and I left there 50GB for ubuntu. I downloaded ubuntu 12.04.3desktop-amd64(64bit), created bootable USB using Universal USB Installer (recommended on Ubuntu site). I disabled USB legacy support (that Ubuntu could be installed in EFI mode- I was following instructions on Ubuntu site), and also Secure Boot (windows is now angry with me because I turned it off- when I start windows it informs me I should enable that). I inserted USB rebooted computer and chose install ubuntu, divided free 50GB space to swap(2000MB) and rest as ext4 main storage space for ubuntu. Installation passed normally, Ubuntu then asked me to reboot computer. After reboot windows 8 started. Now I can't start ubuntu. When I restart win8 to uefi there is possibility to boot ubuntu, but when I choose it, it crashes. When I choose try ubunfu from connected USB, nothing happend, still dark screed. What is wrong? Can you help me? I am in hurry to do it because of school. Thanks.

  Read the article

• Cannot find GRUB - Ubuntu/Windows 8 dual-boot

  - by ubeatlenine

  Hello Ubuntu community, I find myself in an interesting situation. I have a Dell Inspiron 531 with Windows Vista. Recently my brother decided it would be a good idea to overwrite Vista with the Windows 8 consumer preview. Since we have had this PC for a very long time, we have long since lost the Vista CD, and according to the Windows 8 preview website you cannot recover your previous OS without it. I thought this would be a good opportunity to try out Ubuntu (since we obviously cannot keep the preview as an OS), but it appears that Ubuntu 11.10 Desktop is not compatible with Win8. Ubuntu doesn't run from the LiveUSB I made, instead it freezes on the loading screen and then disintegrates into black and white stripes. I blamed this failure on Ubuntu not being compatible with win8 yet and tried to install Ubuntu from the USB on a partition made from the remaining space on my hard drive - about 100GB. However the installer crashed while loading modules and told me I didn't have enough disk space. Since then, I have not been able to load either Ubuntu or Windows, BIOS is shifted over to the left of my screen, and I always get the same message: error: unknown filesystem grub rescue> typing "ls" at the prompt gives me the following: (hd0) (hd0,msdos7) (hd0,msdos6) (hd0,msdos5) (hd0,msdos2) (hd0,msdos1) does this mean I have multiple partitions running windows on my computer? Is it possible to recover Vista without the disk? Are all of my problems stemming from Ubuntu not being compatible with Win8 preview? (I realize the majority of my questions are about Windows, but seeing as the prompt I get is for grub I thought I would ask here first.) Any insight anyone has on this predicament would be greatly appreciated.

  Read the article

• Help reinstalling Ubuntu on macbook pro

  - by pipsqueaker117

  Ok. I recently installed ubuntu on my macbook pro. Unfortunately, while trying to install the nvidia graphics drivers the system wouldn't reboot, the screen grey for hours. I concluded that I had broken ubuntu, and proceeded to boot into osx and remove the ubuntu partitions. After I had done that, after a reboot, I noticed that "boot linux from hd" was still listed in the bootloader (i'm using rEFIT). I dismissed it. Now, I'm trying to reinstall ubuntu, using the same USB that I successfully installed with earlier. Now, however, when the ubuntu installer is on the "copying files" part this error (more or less) pops up. ERRNO 5: We're sorry, the installer crashed. This error frequently is caused by faulty installation media, the hard disk being too hot... and so on and so forth. I'm not sure what's causing the problem, but I have a hunch that whatever's the reason that's causing linux to show up in rEFIT is the root reason. If anyone could respond, that would be great. PS, and unfortunately no, i do not have a time machine backup.

  Read the article

• Just installed Ubuntu 12.04. When booting, all I get is a black screen with cursor

  - by user66378

  Installation appears to go fine. After rebooting, I get my motherboard loading screens, but when it comes time for Ubuntu to boot, I just get a black screen with a blinking white underscore in the top-left - same as I got when waiting for the install CD to load, except it lasts forever. The only keypress it seems to recognize is ctrl+alt+del, which reboots. Letters don't register, function keys w/ or w/o modifiers do nothing. I've installed Ubuntu 12.04 twice and got the same error. The first time, I installed it as the only OS, and had it take up the whole disk. The second time, I installed Windows 7 first, then Ubuntu by specifying custom partitions. After this install, it would boot straight to Windows without showing grub. I used EasyBCD to add the Ubuntu installation to grub, and this got grub to show, and let me select it, but it led back to the same error described up top. I've had Linux Mint 11 and 12 installed on this PC, but was unable to get previous versions of Ubuntu to install (always had errors while installing, not after). Hardware: Intel Core i7-2600K Sandy Bridge 3.4GHz (3.8GHz Turbo Boost) LGA 1155 ASUS SABERTOOTH P67 (REV 3.0) LGA 1155 Intel P67 SATA 6Gb/s USB 3.0 ATX Intel Motherboard EVGA 01G-P3-1371-TR GeForce GTX 460 (Fermi) CORSAIR Vengeance 16GB (4 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Western Digital RE4 WD5003ABYX 500GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive

  Read the article

• Delete Ubuntu and Grub from PC (and BIOS unaccessible)

  - by Temitope

  I've really done a mess while upgrading 12.04 to 12.10, or my PC did, or ubuntu did, I can't really tell. The situation now is I have a dual booting machine, Windows 7 and ubuntu 12.10 -When turning on the PC, I can't access boot options, I've tried every thing, esc, f1 f8, f10 (I have a Hp pavilion) but all I can see is a short-lasting screen with three lines reading something like "error:files not found" or "link not found". So the PC turns to the Grub loader screen. This is already a BIG problem. It means I can't change boot order, and I'm diperate, since it doensn't seem that repairing my operating systems will bring my BIOS back. -If I chose Ubuntu in grup, it loades but then frezes on the desktop, I may be having problem with unity3d, or compiz, which was reported to be crashing the first times I started ubuntu. Now, after turning off and on the pc several times, no crash is reported again. Ubuntu just load my background image and nothing else. Not the side menu, not the header, nothing. Althogh the system seems "functioning", when I press the power button on the PC, for example, the normal shutdown dialog window appears. -If I chose Windows, Grubs tells me that something is not found, and to press any key to continue; I do it and then Windows loads perfectly. What I now want to do is 1- use EasyBSD to change boot order and boot Windows partition first 2- delete the ubuntu partitions from within windows disk manager What I except happening is that My PC turns to, or near to factory booting settings: I press the power button and Windows loads without asking me nothing I have acess to all my hardisk from withing windows Is that what will really happen? Are there danger I'm not seeing? What I don't except happening is The BIOS access key return functioning How could I eventually solve this? I would like to reinstall Ubuntu, 32 bit version this time.

  Read the article

• Ubuntu 12.04 login screen flickers. “Could not write bytes: broken pipes”

  - by Brayn

  I use Ubuntu 12.04 x64 with a dual-boot setup. Yesterday it worked fine but this morning when I attempted to boot it gets to the login screen and then it just flickers, alternating between the login screen and the console showing boot items (mainly Apache, the last one being "Battery status" although it's a desktop) all with [OK] status. The only error that I can see is: "Could not write bytes: broken pipes" on top of the screen. The only things I can think of that could cause this are: This morning I had a removable hdd plugged in during boot time, which I usually don't have Yesterday I've installed Dwarven Fortress that requires some x32 libraries so I've installed ia32 using synaptic. As far as I know this shouldn't brake the system but I didn't reboot yesterday so I can't be sure. I've tried booting in recovery mode and tried running the utils there but still no luck. I've ran out of ideas. Thanks. EDIT: Forgot to mention that all partitions have plenty of free space EDIT2: In the end I just reinstalled Ubuntu as time was of the essence.

  Read the article

• Why does Ubuntu 12.10 Beta2 insist on commiting changes to the partition table?

  - by Uten

  Why does Ubuntu 12.10 Beta2 insist on commiting changes to the partition table even as no real changes has been done? This is a show stopper for me as I'm installing without a CD/DVD ROM. This is how I go about it. I downloaded the iso image and extracted vmlinuz and initrd.lz to the same folder I keep the iso image. Configured grub (0.9x) to boot /ubuntu/vmlinuz with the iso image like this: title ubuntu live-cd kernel /ubuntu/vmlinuz boot=casper iso-scan/filename=/ubuntu/ubuntu-12.10-beta2-desktop-i386.iso ro quiet splash initrd /ubuntu/initrd.lz boot This works well and I get a running livecd session. The iso image is mounted on /isomedia (or something similar). The spare HD space where I want to install Ubuntu is in the logical area (at the wery end of the disk). I have tried both to use the space as empty and preformated with ext4. After selecting the partition and selecting "use as ext4" and selecting a mountpoint (/) I get the message: "The installer needs to commit changes to partition tables, but cannot do so because partitions on the following mount points could not be unmounted" "/isomedia" (or something similar). Is this a "feature" of the installer? To insist that everything is unmounted even if no changes is nescesary (as fare as I understand). It's probably a safety feature but is it needed? I have cahnged layouts with parted and gparted (at the end of the disk) for years without any failures. I understand that booting the iso image like this is not the common way. But it is just such a beautifull way of doing it when you hav a running system and want to play with another. Any one had any success installing Ubuntu (12.10 beta2 ) like this? Best regards Uten

  Read the article

• Growing your VirtualBox Virtual Disk

  - by Fat Bloke

  Don't you just hate it when this happens: Fortunately, if you're running inside VirtualBox, you can resize your virtual disk and magically make your guest have a bigger disk very easily. There are 2 steps to doing this... 1. Resize the virtual disk Use the VBoxManage command line tool to extend the size of the Virtual Disk, specifying the path to the disk and the size in MB: VBoxManage modifyhd <uuid>|<filename> [--type normal|writethrough|immutable|shareable| readonly|multiattach] [--autoreset on|off] [--compact] [--resize <megabytes>|--resizebyte <bytes>]   If you booted up your guest at this point, the extra space is seen as an unformatted area on the disk, like this: So we now need to tell the guest about the extra space available. 2. Extend the guest's partition to use the extra space How you do this step depends on you guest OS type and the tools you have available. Linux guests often include the excellent gparted partition editor, whereas Windows 7 and 8 provide the Computer Management tool which can resize partitions. Unfortunately, my Windows XP vm has no such tool. But I do have a couple of other options: Most Linux installable .isos include the aforementioned gparted tool, so I could simply attach, say, an Ubuntu.iso as a Virtual CD/DVD in my Windows XP vm and boot off that. Then use gparted to extend the Windows XP partition, before finally rebooting. But I took another route and attached my resized virtual disk to a Windows Server 2012 vm I had lying around. Then I used the Computer Management tool in Windows Server 2012 to extend the partition of the Windows XP disk, before shutting down, unplugging the disk and reattaching to my Windows XP vm. (Note that if your vm's use different disk controllers, Windows will check the disks on booting). When I finally boot up my Windows XP guest I see the available disk space and all is well. At least until the next time - FB 

  Read the article

• Sorting Algorithms

  - by MarkPearl

  General Every time I go back to university I find myself wading through sorting algorithms and their implementation in C++. Up to now I haven’t really appreciated their true value. However as I discovered this last week with Dictionaries in C# – having a knowledge of some basic programming principles can greatly improve the performance of a system and make one think twice about how to tackle a problem. I’m going to cover briefly in this post the following: Selection Sort Insertion Sort Shellsort Quicksort Mergesort Heapsort (not complete) Selection Sort Array based selection sort is a simple approach to sorting an unsorted array. Simply put, it repeats two basic steps to achieve a sorted collection. It starts with a collection of data and repeatedly parses it, each time sorting out one element and reducing the size of the next iteration of parsed data by one. So the first iteration would go something like this… Go through the entire array of data and find the lowest value Place the value at the front of the array The second iteration would go something like this… Go through the array from position two (position one has already been sorted with the smallest value) and find the next lowest value in the array. Place the value at the second position in the array This process would be completed until the entire array had been sorted. A positive about selection sort is that it does not make many item movements. In fact, in a worst case scenario every items is only moved once. Selection sort is however a comparison intensive sort. If you had 10 items in a collection, just to parse the collection you would have 10+9+8+7+6+5+4+3+2=54 comparisons to sort regardless of how sorted the collection was to start with. If you think about it, if you applied selection sort to a collection already sorted, you would still perform relatively the same number of iterations as if it was not sorted at all. Many of the following algorithms try and reduce the number of comparisons if the list is already sorted – leaving one with a best case and worst case scenario for comparisons. Likewise different approaches have different levels of item movement. Depending on what is more expensive, one may give priority to one approach compared to another based on what is more expensive, a comparison or a item move. Insertion Sort Insertion sort tries to reduce the number of key comparisons it performs compared to selection sort by not “doing anything” if things are sorted. Assume you had an collection of numbers in the following order… 10 18 25 30 23 17 45 35 There are 8 elements in the list. If we were to start at the front of the list – 10 18 25 & 30 are already sorted. Element 5 (23) however is smaller than element 4 (30) and so needs to be repositioned. We do this by copying the value at element 5 to a temporary holder, and then begin shifting the elements before it up one. So… Element 5 would be copied to a temporary holder 10 18 25 30 23 17 45 35 – T 23 Element 4 would shift to Element 5 10 18 25 30 30 17 45 35 – T 23 Element 3 would shift to Element 4 10 18 25 25 30 17 45 35 – T 23 Element 2 (18) is smaller than the temporary holder so we put the temporary holder value into Element 3. 10 18 23 25 30 17 45 35 – T 23   We now have a sorted list up to element 6. And so we would repeat the same process by moving element 6 to a temporary value and then shifting everything up by one from element 2 to element 5. As you can see, one major setback for this technique is the shifting values up one – this is because up to now we have been considering the collection to be an array. If however the collection was a linked list, we would not need to shift values up, but merely remove the link from the unsorted value and “reinsert” it in a sorted position. Which would reduce the number of transactions performed on the collection. So.. Insertion sort seems to perform better than selection sort – however an implementation is slightly more complicated. This is typical with most sorting algorithms – generally, greater performance leads to greater complexity. Also, insertion sort performs better if a collection of data is already sorted. If for instance you were handed a sorted collection of size n, then only n number of comparisons would need to be performed to verify that it is sorted. It’s important to note that insertion sort (array based) performs a number item moves – every time an item is “out of place” several items before it get shifted up. Shellsort – Diminishing Increment Sort So up to now we have covered Selection Sort & Insertion Sort. Selection Sort makes many comparisons and insertion sort (with an array) has the potential of making many item movements. Shellsort is an approach that takes the normal insertion sort and tries to reduce the number of item movements. In Shellsort, elements in a collection are viewed as sub-collections of a particular size. Each sub-collection is sorted so that the elements that are far apart move closer to their final position. Suppose we had a collection of 15 elements… 10 20 15 45 36 48 7 60 18 50 2 19 43 30 55 First we may view the collection as 7 sub-collections and sort each sublist, lets say at intervals of 7 10 60 55 – 20 18 – 15 50 – 45 2 – 36 19 – 48 43 – 7 30 10 55 60 – 18 20 – 15 50 – 2 45 – 19 36 – 43 48 – 7 30 (Sorted) We then sort each sublist at a smaller inter – lets say 4 10 55 60 18 – 20 15 50 2 – 45 19 36 43 – 48 7 30 10 18 55 60 – 2 15 20 50 – 19 36 43 45 – 7 30 48 (Sorted) We then sort elements at a distance of 1 (i.e. we apply a normal insertion sort) 10 18 55 60 2 15 20 50 19 36 43 45 7 30 48 2 7 10 15 18 19 20 30 36 43 45 48 50 55 (Sorted) The important thing with shellsort is deciding on the increment sequence of each sub-collection. From what I can tell, there isn’t any definitive method and depending on the order of your elements, different increment sequences may perform better than others. There are however certain increment sequences that you may want to avoid. An even based increment sequence (e.g. 2 4 8 16 32 …) should typically be avoided because it does not allow for even elements to be compared with odd elements until the final sort phase – which in a way would negate many of the benefits of using sub-collections. The performance on the number of comparisons and item movements of Shellsort is hard to determine, however it is considered to be considerably better than the normal insertion sort. Quicksort Quicksort uses a divide and conquer approach to sort a collection of items. The collection is divided into two sub-collections – and the two sub-collections are sorted and combined into one list in such a way that the combined list is sorted. The algorithm is in general pseudo code below… Divide the collection into two sub-collections Quicksort the lower sub-collection Quicksort the upper sub-collection Combine the lower & upper sub-collection together As hinted at above, quicksort uses recursion in its implementation. The real trick with quicksort is to get the lower and upper sub-collections to be of equal size. The size of a sub-collection is determined by what value the pivot is. Once a pivot is determined, one would partition to sub-collections and then repeat the process on each sub collection until you reach the base case. With quicksort, the work is done when dividing the sub-collections into lower & upper collections. The actual combining of the lower & upper sub-collections at the end is relatively simple since every element in the lower sub-collection is smaller than the smallest element in the upper sub-collection. Mergesort With quicksort, the average-case complexity was O(nlog2n) however the worst case complexity was still O(N*N). Mergesort improves on quicksort by always having a complexity of O(nlog2n) regardless of the best or worst case. So how does it do this? Mergesort makes use of the divide and conquer approach to partition a collection into two sub-collections. It then sorts each sub-collection and combines the sorted sub-collections into one sorted collection. The general algorithm for mergesort is as follows… Divide the collection into two sub-collections Mergesort the first sub-collection Mergesort the second sub-collection Merge the first sub-collection and the second sub-collection As you can see.. it still pretty much looks like quicksort – so lets see where it differs… Firstly, mergesort differs from quicksort in how it partitions the sub-collections. Instead of having a pivot – merge sort partitions each sub-collection based on size so that the first and second sub-collection of relatively the same size. This dividing keeps getting repeated until the sub-collections are the size of a single element. If a sub-collection is one element in size – it is now sorted! So the trick is how do we put all these sub-collections together so that they maintain their sorted order. Sorted sub-collections are merged into a sorted collection by comparing the elements of the sub-collection and then adjusting the sorted collection. Lets have a look at a few examples… Assume 2 sub-collections with 1 element each 10 & 20 Compare the first element of the first sub-collection with the first element of the second sub-collection. Take the smallest of the two and place it as the first element in the sorted collection. In this scenario 10 is smaller than 20 so 10 is taken from sub-collection 1 leaving that sub-collection empty, which means by default the next smallest element is in sub-collection 2 (20). So the sorted collection would be 10 20 Lets assume 2 sub-collections with 2 elements each 10 20 & 15 19 So… again we would Compare 10 with 15 – 10 is the winner so we add it to our sorted collection (10) leaving us with 20 & 15 19 Compare 20 with 15 – 15 is the winner so we add it to our sorted collection (10 15) leaving us with 20 & 19 Compare 20 with 19 – 19 is the winner so we add it to our sorted collection (10 15 19) leaving us with 20 & _ 20 is by default the winner so our sorted collection is 10 15 19 20. Make sense? Heapsort (still needs to be completed) So by now I am tired of sorting algorithms and trying to remember why they were so important. I think every year I go through this stuff I wonder to myself why are we made to learn about selection sort and insertion sort if they are so bad – why didn’t we just skip to Mergesort & Quicksort. I guess the only explanation I have for this is that sometimes you learn things so that you can implement them in future – and other times you learn things so that you know it isn’t the best way of implementing things and that you don’t need to implement it in future. Anyhow… luckily this is going to be the last one of my sorts for today. The first step in heapsort is to convert a collection of data into a heap. After the data is converted into a heap, sorting begins… So what is the definition of a heap? If we have to convert a collection of data into a heap, how do we know when it is a heap and when it is not? The definition of a heap is as follows: A heap is a list in which each element contains a key, such that the key in the element at position k in the list is at least as large as the key in the element at position 2k +1 (if it exists) and 2k + 2 (if it exists). Does that make sense? At first glance I’m thinking what the heck??? But then after re-reading my notes I see that we are doing something different – up to now we have really looked at data as an array or sequential collection of data that we need to sort – a heap represents data in a slightly different way – although the data is stored in a sequential collection, for a sequential collection of data to be in a valid heap – it is “semi sorted”. Let me try and explain a bit further with an example… Example 1 of Potential Heap Data Assume we had a collection of numbers as follows 1[1] 2[2] 3[3] 4[4] 5[5] 6[6] For this to be a valid heap element with value of 1 at position [1] needs to be greater or equal to the element at position [3] (2k +1) and position [4] (2k +2). So in the above example, the collection of numbers is not in a valid heap. Example 2 of Potential Heap Data Lets look at another collection of numbers as follows 6[1] 5[2] 4[3] 3[4] 2[5] 1[6] Is this a valid heap? Well… element with the value 6 at position 1 must be greater or equal to the element at position [3] and position [4]. Is 6 > 4 and 6 > 3? Yes it is. Lets look at element 5 as position 2. It must be greater than the values at [4] & [5]. Is 5 > 3 and 5 > 2? Yes it is. If you continued to examine this second collection of data you would find that it is in a valid heap based on the definition of a heap.

  Read the article

• "device-mapper resume ioctl failed" when run a instance

  - by user1490377

  I install ubuntu-12.04 server and openstack on two computer. When Launch an image, the instance can't run and show error state! nova-compute.log details: 2012-06-24 12:02:00 DEBUG nova.utils [req-71fdca27-5f93-438e-a4be-ddc54f698171 c737b66b2102415f817ca50b9649fd8f 5b1da4eaee3643919a230efc06473720] Unexpected error while running command. Command: sudo nova-rootwrap kpartx -a /dev/nbd15 Exit code: 1 Stdout: '' Stderr: 'device-mapper: resume ioctl failed: Invalid argument\ncreate/reload failed on nbd15p1\n' from (pid=1267) trycmd /usr/lib/python2.7/dist-packages/nova/utils.py:277 2012-06-24 12:02:00 DEBUG nova.utils [req-71fdca27-5f93-438e-a4be-ddc54f698171 c737b66b2102415f817ca50b9649fd8f 5b1da4eaee3643919a230efc06473720] Running cmd (subprocess): sudo nova-rootwrap qemu-nbd -d /dev/nbd15 from (pid=1267) execute /usr/lib/python2.7/dist-packages/nova/utils.py:219 2012-06-24 12:02:02 DEBUG nova.virt.disk.api [req-71fdca27-5f93-438e-a4be-ddc54f698171 c737b66b2102415f817ca50b9649fd8f 5b1da4eaee3643919a230efc06473720] Failed to map partitions: Unexpected error while running command. Command: sudo nova-rootwrap kpartx -a /dev/nbd15 Exit code: 1 Stdout: '' Stderr: 'device-mapper: resume ioctl failed: Invalid argument\ncreate/reload failed on nbd15p1\n' from (pid=1267) mount /usr/lib/python2.7/dist-packages/nova/virt/disk/api.py:205

  Read the article

• Very large database, very small portion most being retrieved in real time

  - by ming yeow

  Hi folks, I have an interesting database problem. I have a DB that is 150GB in size. My memory buffer is 8GB. Most of my data is rarely being retrieved, or mainly being retrieved by backend processes. I would very much prefer to keep them around because some features require them. Some of it (namely some tables, and some identifiable parts of certain tables) are used very often in a user facing manner How can I make sure that the latter is always being kept in memory? (there is more than enough space for these) More info: We are on Ruby on rails. The database is MYSQL, our tables are stored using INNODB. We are sharding the data across 2 partitions. Because we are sharding it, we store most of our data using JSON blobs, while indexing only the primary keys

  Read the article

• MP4 plays on Safari 4 (desktop) but not on Safari Mobile (iphone)

  - by deb

  I'm encoding the video with ffmpeg and displaying it using the HTML 5 video tag. It works fine on Firefox (i'm also providing a ogg version) and Safari 4. However, when I try to open it on the iphone I get a "Cannot Play Movie" error. Here is the ffmpeg command I'm using: ffmpeg -y -i movie.mov -acodec libfaac -ar 44100 -ab 96k -vcodec libx264 -vpre hq -level 41 -crf 20 -bufsize 20000k -maxrate 1500k -g 250 -s 320X200 -coder 1 -flags +loop -cmp +chroma -partitions +parti4x4+partp8x8+partb8x8 -flags2 +dct8x8+bpyramid -me_method umh -subq 7 -me_range 16 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -rc_eq 'blurCplx^(1-qComp)' -bf 16 -b_strategy 1 -bidir_refine 1 -refs 6 -deblockalpha 0 -deblockbeta 0 movie.mp4 I reduced the maxrate to 1500 because I read that if the bit rate is too high the iphone won't play the video, but still didn't work. I don't know where else to look... any ideas? Thanks in advance

  Read the article

• Associate mount points with local disks in VBscript / WMI

  - by Mark Unwin

  I have a VBscript that outputs various config items about a system. Both hardware and software. I can output disks and their associated partitions. I can output mount points. I do not seem to be able to associate a mount point with a local disk (where it actually is a local disk). I need to be able to do this using VBscript, so as to fit in with the rest of the ~2000 lines of code. I do NOT want to run some other program graphically. I know the disk manager service can show me (My Computer - Manage - Disk Management), but this is not what I need. I need to be able to do this remotely via VBscript. I am open to running an .exe from the VBscript and piping the output back into VBscript and massaging it from there. Any idea's ? Thanks in advance.

  Read the article

• about Randomized-select algorithm

  - by matin1234

  Hi I have this array A = <3,2,9,0,7,5,4,8,6,1> and I want to write all its worst partitions are these correct?thanks a1 = <0,2,9,3,7,5,4,8,6,1> a2 = <1,9,3,7,5,4,8,6,2> a3 = <2,3,7,5,4,8,6,9> a4 = <3,7,5,4,8,6,9> a5 = <4,5,7,8,6,9> a6 = <5,7,8,6,9> a7 = <6,8,7,9> a8 = <7,8,9> a9 = <8,9> a10 = <9>

  Read the article

• Hard Disk DRDY error: is it a crash

  - by pranjal

  I am using IBM Thinkpad, 1.7GHz, 512 RAM with Linux Mint 9 installed. I have two partitions in addition to root. One of the partitions became read-only yesterday, after which I rebooted my system. It is extremely slow along with DRDY Error : Is my Hard disk crashed ? Error Log while booting. Differences between boot sector and its backup. failed command : READ DMA BMDMA : stat 0X25 ata 1.00 : status : { DRDY ERR } ata 1.00 : status :{ UNC } Buffer I/O error on logical device, logical block 65467 smartctl output for the partition: mint mint # smartctl -a /dev/sda1 smartctl version 5.38 [i686-pc-linux-gnu] Copyright (C) 2002-8 Bruce Allen Home page is http://smartmontools.sourceforge.net/ === START OF INFORMATION SECTION === Device Model: TOSHIBA MK4026GAX RoHS Serial Number: X5LY1623T Firmware Version: PA107E User Capacity: 40,007,761,920 bytes Device is: Not in smartctl database [for details use: -P showall] ATA Version is: 6 ATA Standard is: Exact ATA specification draft version not indicated Local Time is: Thu Feb 17 06:48:25 2011 UTC SMART support is: Available - device has SMART capability. SMART support is: Enabled === START OF READ SMART DATA SECTION === SMART overall-health self-assessment test result: PASSED General SMART Values: Offline data collection status: (0x84) Offline data collection activity was suspended by an interrupting command from host. Auto Offline Data Collection: Enabled. Self-test execution status: ( 0) The previous self-test routine completed without error or no self-test has ever been run. Total time to complete Offline data collection: ( 153) seconds. Offline data collection capabilities: (0x1b) SMART execute Offline immediate. Auto Offline data collection on/off support. Suspend Offline collection upon new command. Offline surface scan supported. Self-test supported. No Conveyance Self-test supported. No Selective Self-test supported. SMART capabilities: (0x0003) Saves SMART data before entering power-saving mode. Supports SMART auto save timer. Error logging capability: (0x01) Error logging supported. No General Purpose Logging support. Short self-test routine recommended polling time: ( 2) minutes. Extended self-test routine recommended polling time: ( 30) minutes. SMART Attributes Data Structure revision number: 16 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000b 100 100 050 Pre-fail Always - 0 2 Throughput_Performance 0x0005 100 100 050 Pre-fail Offline - 0 3 Spin_Up_Time 0x0027 100 100 001 Pre-fail Always - 310 4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 3968 5 Reallocated_Sector_Ct 0x0033 100 100 050 Pre-fail Always - 40 7 Seek_Error_Rate 0x000b 100 100 050 Pre-fail Always - 0 8 Seek_Time_Performance 0x0005 100 100 050 Pre-fail Offline - 0 9 Power_On_Hours 0x0032 082 082 000 Old_age Always - 7257 10 Spin_Retry_Count 0x0033 179 100 030 Pre-fail Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 3484 192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age Always - 489 193 Load_Cycle_Count 0x0032 064 064 000 Old_age Always - 367150 194 Temperature_Celsius 0x0022 100 100 000 Old_age Always - 36 (Lifetime Min/Max 14/57) 196 Reallocated_Event_Count 0x0032 100 100 000 Old_age Always - 33 197 Current_Pending_Sector 0x0032 100 100 000 Old_age Always - 82 198 Offline_Uncorrectable 0x0030 100 100 000 Old_age Offline - 1 199 UDMA_CRC_Error_Count 0x0032 200 253 000 Old_age Always - 0 220 Disk_Shift 0x0002 100 100 000 Old_age Always - 101 222 Loaded_Hours 0x0032 085 085 000 Old_age Always - 6146 223 Load_Retry_Count 0x0032 100 100 000 Old_age Always - 0 224 Load_Friction 0x0022 100 100 000 Old_age Always - 0 226 Load-in_Time 0x0026 100 100 000 Old_age Always - 227 240 Head_Flying_Hours 0x0001 100 100 001 Pre-fail Offline - 0 SMART Error Log Version: 1 ATA Error Count: 2371 (device log contains only the most recent five errors) CR = Command Register [HEX] FR = Features Register [HEX] SC = Sector Count Register [HEX] SN = Sector Number Register [HEX] CL = Cylinder Low Register [HEX] CH = Cylinder High Register [HEX] DH = Device/Head Register [HEX] DC = Device Command Register [HEX] ER = Error register [HEX] ST = Status register [HEX] Powered_Up_Time is measured from power on, and printed as DDd+hh:mm:SS.sss where DD=days, hh=hours, mm=minutes, SS=sec, and sss=millisec. It "wraps" after 49.710 days. Error 2371 occurred at disk power-on lifetime: 7256 hours (302 days + 8 hours) When the command that caused the error occurred, the device was active or idle. After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 40 51 05 1a 1b 00 e0 Error: UNC 5 sectors at LBA = 0x00001b1a = 6938 Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- c8 00 05 1a 1b 00 e0 00 00:03:10.061 READ DMA f8 00 00 00 00 00 e0 00 00:03:10.061 READ NATIVE MAX ADDRESS ec 00 00 00 00 00 a0 02 00:03:10.053 IDENTIFY DEVICE ef 03 45 00 00 00 a0 02 00:03:10.053 SET FEATURES [Set transfer mode] f8 00 00 00 00 00 e0 00 00:03:10.053 READ NATIVE MAX ADDRESS Error 2370 occurred at disk power-on lifetime: 7256 hours (302 days + 8 hours) When the command that caused the error occurred, the device was active or idle. After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 40 51 05 1a 1b 00 e0 Error: UNC 5 sectors at LBA = 0x00001b1a = 6938 Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- c8 00 05 1a 1b 00 e0 00 00:03:03.328 READ DMA f8 00 00 00 00 00 e0 00 00:03:03.327 READ NATIVE MAX ADDRESS ec 00 00 00 00 00 a0 02 00:03:03.320 IDENTIFY DEVICE ef 03 45 00 00 00 a0 02 00:03:03.319 SET FEATURES [Set transfer mode] f8 00 00 00 00 00 e0 00 00:03:03.319 READ NATIVE MAX ADDRESS Error 2369 occurred at disk power-on lifetime: 7256 hours (302 days + 8 hours) When the command that caused the error occurred, the device was active or idle. After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 40 51 05 1a 1b 00 e0 Error: UNC 5 sectors at LBA = 0x00001b1a = 6938 Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- c8 00 05 1a 1b 00 e0 00 00:02:56.582 READ DMA f8 00 00 00 00 00 e0 00 00:02:56.582 READ NATIVE MAX ADDRESS ec 00 00 00 00 00 a0 02 00:02:56.574 IDENTIFY DEVICE ef 03 45 00 00 00 a0 02 00:02:56.574 SET FEATURES [Set transfer mode] f8 00 00 00 00 00 e0 00 00:02:56.574 READ NATIVE MAX ADDRESS Error 2368 occurred at disk power-on lifetime: 7256 hours (302 days + 8 hours) When the command that caused the error occurred, the device was active or idle. After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 40 51 05 1a 1b 00 e0 Error: UNC 5 sectors at LBA = 0x00001b1a = 6938 Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- c8 00 05 1a 1b 00 e0 00 00:02:49.809 READ DMA f8 00 00 00 00 00 e0 00 00:02:49.809 READ NATIVE MAX ADDRESS ec 00 00 00 00 00 a0 02 00:02:49.801 IDENTIFY DEVICE ef 03 45 00 00 00 a0 02 00:02:49.801 SET FEATURES [Set transfer mode] f8 00 00 00 00 00 e0 00 00:02:49.801 READ NATIVE MAX ADDRESS Error 2367 occurred at disk power-on lifetime: 7256 hours (302 days + 8 hours) When the command that caused the error occurred, the device was active or idle. After command completion occurred, registers were: ER ST SC SN CL CH DH -- -- -- -- -- -- -- 40 51 05 1a 1b 00 e0 Error: UNC 5 sectors at LBA = 0x00001b1a = 6938 Commands leading to the command that caused the error were: CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name -- -- -- -- -- -- -- -- ---------------- -------------------- c8 00 05 1a 1b 00 e0 00 00:02:43.056 READ DMA f8 00 00 00 00 00 e0 00 00:02:43.056 READ NATIVE MAX ADDRESS ec 00 00 00 00 00 a0 02 00:02:43.048 IDENTIFY DEVICE ef 03 45 00 00 00 a0 02 00:02:43.048 SET FEATURES [Set transfer mode] f8 00 00 00 00 00 e0 00 00:02:43.047 READ NATIVE MAX ADDRESS SMART Self-test log structure revision number 1 No self-tests have been logged. [To run self-tests, use: smartctl -t] Device does not support Selective Self Tests/Logging Do I need to get a new Hard Disk my PC ?

  Read the article

• Studying MySQL, SQLite source code to learn about RDBMS implementation

  - by Yang

  I know implementing database is a huge topic, but I want to have a basic understanding of how database systems work (e.g. memory management, binary tree, transaction, sql parsing, multi-threading, partitions, etc) by investigating the source code of the database. Since there are a few already proven very robust open source databases like mysql, sqlite and so on. However, the code are very complicated and I have no clue where to start. Also I find that the old school database textbooks are only explaining the theory, not the implementation details. Can anyone suggest how I should get started and if there are any books that emphasis on the technology and techniques of building dbms used in modern database industry?

  Read the article

• problems mounting an external IDE drive via USB in ubuntu

  - by Roy Rico

  I am having a problem connecting a specific IDE drive to my linux box. It's an old drive which I just want to get about 3 GB of files off of. INFO I am trying to connect a 200GB IDE Maxtor Drive, internally and externally... externally: I am using an self powered USB IDE external drive enclosure which I have used to connect various drives, under ubuntu and windows, in the past. The other posts stated it coudl be a problem I think i may have formatted the /dev/sdc partition instead of /dev/sdc1 partition when i originally formatted the drive. internally: I only have one machine left that has an internal IDE interface, and it's got XP on it. I plugged this drive internally into this machine with windows XP and used the ext2/ext3 drivers to mount this drive, but some files have question marks (?) in the file names which is messing up my copy process in windows. I can't delete the files under windows. Ubuntu Linux will not install on my only remaining machine that has IDE controller. I have tried the suggestions in the questions below http://superuser.com/questions/88182/mount-an-external-drive-in-ubuntu http://superuser.com/questions/23210/ubuntu-fails-to-mount-usb-drive it looks like i can see the drive in /proc/partitions $ cat /proc/partitions major minor #blocks name 8 0 78125000 sda 8 1 74894998 sda1 8 2 1 sda2 8 5 3229033 sda5 8 16 199148544 sdb <-- could be my drive? but it's not listed under fdisk -l $ fdisk -l Disk /dev/sda: 80.0 GB, 80000000000 bytes 255 heads, 63 sectors/track, 9726 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xd0f4738c Device Boot Start End Blocks Id System /dev/sda1 * 1 9324 74894998+ 83 Linux /dev/sda2 9325 9726 3229065 5 Extended /dev/sda5 9325 9726 3229033+ 82 Linux swap / Solaris and here is my log of /var/log/messages. with a bunch of weird output, can someone let me know what that weird output is? Mar 3 19:49:40 mala kernel: [687455.112029] usb 1-7: new high speed USB device using ehci_hcd and address 3 Mar 3 19:49:41 mala kernel: [687455.248576] usb 1-7: configuration #1 chosen from 1 choice Mar 3 19:49:41 mala kernel: [687455.267450] Initializing USB Mass Storage driver... Mar 3 19:49:41 mala kernel: [687455.269180] scsi4 : SCSI emulation for USB Mass Storage devices Mar 3 19:49:41 mala kernel: [687455.269410] usbcore: registered new interface driver usb-storage Mar 3 19:49:41 mala kernel: [687455.269416] USB Mass Storage support registered. Mar 3 19:49:46 mala kernel: [687460.270917] scsi 4:0:0:0: Direct-Access Maxtor 6 Y200P0 YAR4 PQ: 0 ANSI: 2 Mar 3 19:49:46 mala kernel: [687460.271485] sd 4:0:0:0: Attached scsi generic sg2 type 0 Mar 3 19:49:46 mala kernel: [687460.278858] sd 4:0:0:0: [sdb] 398297088 512-byte logical blocks: (203 GB/189 GiB) Mar 3 19:49:46 mala kernel: [687460.280866] sd 4:0:0:0: [sdb] Write Protect is off Mar 3 19:50:16 mala kernel: [687460.283784] sdb: Mar 3 19:50:16 mala kernel: [687491.112020] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:50:47 mala kernel: [687522.120030] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:51:18 mala kernel: [687553.112034] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:51:49 mala kernel: [687584.116025] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:52:02 mala kernel: [687596.170632] type=1505 audit(1267671122.035:31): operation="profile_replace" pid=8426 name=/usr/lib/cups/backend/cups-pdf Mar 3 19:52:02 mala kernel: [687596.171551] type=1505 audit(1267671122.035:32): operation="profile_replace" pid=8426 name=/usr/sbin/cupsd Mar 3 19:52:06 mala kernel: [687600.908056] async/0 D c08145c0 0 7655 2 0x00000000 Mar 3 19:52:06 mala kernel: [687600.908062] e5601d38 00000046 e5774000 c08145c0 e4c2a848 c08145c0 d203973a 0002713d Mar 3 19:52:06 mala kernel: [687600.908072] c08145c0 c08145c0 e4c2a848 c08145c0 00000000 0002713d c08145c0 f0a98c00 Mar 3 19:52:06 mala kernel: [687600.908079] e4c2a5b0 c20125c0 00000002 e5601d80 e5601d44 c056f3be e5601d78 e5601d4c Mar 3 19:52:06 mala kernel: [687600.908087] Call Trace: Mar 3 19:52:06 mala kernel: [687600.908099] [<c056f3be>] io_schedule+0x1e/0x30 Mar 3 19:52:06 mala kernel: [687600.908107] [<c01b2cf5>] sync_page+0x35/0x40 Mar 3 19:52:06 mala kernel: [687600.908111] [<c056f8f7>] __wait_on_bit_lock+0x47/0x90 Mar 3 19:52:06 mala kernel: [687600.908115] [<c01b2cc0>] ? sync_page+0x0/0x40 Mar 3 19:52:06 mala kernel: [687600.908121] [<c020f390>] ? blkdev_readpage+0x0/0x20 Mar 3 19:52:06 mala kernel: [687600.908125] [<c01b2ca9>] __lock_page+0x79/0x80 Mar 3 19:52:06 mala kernel: [687600.908130] [<c015c130>] ? wake_bit_function+0x0/0x50 Mar 3 19:52:06 mala kernel: [687600.908135] [<c01b459f>] read_cache_page_async+0xbf/0xd0 Mar 3 19:52:06 mala kernel: [687600.908139] [<c01b45c2>] read_cache_page+0x12/0x60 Mar 3 19:52:06 mala kernel: [687600.908144] [<c0232dca>] read_dev_sector+0x3a/0x80 Mar 3 19:52:06 mala kernel: [687600.908148] [<c0233d3e>] adfspart_check_ICS+0x1e/0x160 Mar 3 19:52:06 mala kernel: [687600.908152] [<c023339f>] ? disk_name+0xaf/0xc0 Mar 3 19:52:06 mala kernel: [687600.908157] [<c0233d20>] ? adfspart_check_ICS+0x0/0x160 Mar 3 19:52:06 mala kernel: [687600.908161] [<c02334de>] check_partition+0x10e/0x180 Mar 3 19:52:06 mala kernel: [687600.908165] [<c02335f6>] rescan_partitions+0xa6/0x330 Mar 3 19:52:06 mala kernel: [687600.908171] [<c0312472>] ? kobject_get+0x12/0x20 Mar 3 19:52:06 mala kernel: [687600.908175] [<c0312472>] ? kobject_get+0x12/0x20 Mar 3 19:52:06 mala kernel: [687600.908180] [<c039fc43>] ? get_device+0x13/0x20 Mar 3 19:52:06 mala kernel: [687600.908185] [<c03c263f>] ? sd_open+0x5f/0x1b0 Mar 3 19:52:06 mala kernel: [687600.908189] [<c020fda0>] __blkdev_get+0x140/0x310 Mar 3 19:52:06 mala kernel: [687600.908194] [<c020f0ac>] ? bdget+0xec/0x100 Mar 3 19:52:06 mala kernel: [687600.908198] [<c020ff7a>] blkdev_get+0xa/0x10 Mar 3 19:52:06 mala kernel: [687600.908202] [<c0232f30>] register_disk+0x120/0x140 Mar 3 19:52:06 mala kernel: [687600.908207] [<c0308b4d>] ? blk_register_region+0x2d/0x40 Mar 3 19:52:06 mala kernel: [687600.908211] [<c03084f0>] ? exact_match+0x0/0x10 Mar 3 19:52:06 mala kernel: [687600.908216] [<c0308cf0>] add_disk+0x80/0x140 Mar 3 19:52:06 mala kernel: [687600.908221] [<c03084f0>] ? exact_match+0x0/0x10 Mar 3 19:52:06 mala kernel: [687600.908225] [<c0308860>] ? exact_lock+0x0/0x20 Mar 3 19:52:06 mala kernel: [687600.908230] [<c03c53df>] sd_probe_async+0xff/0x1c0

  Read the article

• mysql, sqlite database source code

  - by Yang

  hi guys, i know implementing database is a huge topic, but i want to have a basic understanding of how database systems works (e.g. memory management, binary tree, transaction, sql parsing, multi-threading, partitions, etc) by investigating the source code of the database, since there are a few already proven very robust open source databases like mysql, sqlite and so on. however, the code are very complicated and i have no clue where to start. also i find that the old school database textbooks are only explaining the theory, not the implementation details. Can anyone suggest how should i get started and is there any books that emphasis on the technology and techniques of building dbms used in modern database industry? Thank in advance!

  Read the article

• problems mounting an external IDE drive via USB in ubuntu

  - by Roy Rico

  I am having a problem connecting a specific IDE drive to my linux box. It's an old drive which I just want to get about 3 GB of files off of. INFO I am trying to connect a 200GB IDE Maxtor Drive, internally and externally... externally: I am using an self powered USB IDE external drive enclosure which I have used to connect various drives, under ubuntu and windows, in the past. The other posts stated it coudl be a problem I think i may have formatted the /dev/sdc partition instead of /dev/sdc1 partition when i originally formatted the drive. internally: I only have one machine left that has an internal IDE interface, and it's got XP on it. I plugged this drive internally into this machine with windows XP and used the ext2/ext3 drivers to mount this drive, but some files have question marks (?) in the file names which is messing up my copy process in windows. I can't delete the files under windows. Ubuntu Linux will not install on my only remaining machine that has IDE controller. I have tried the suggestions in the questions below http://superuser.com/questions/88182/mount-an-external-drive-in-ubuntu http://superuser.com/questions/23210/ubuntu-fails-to-mount-usb-drive it looks like i can see the drive in /proc/partitions $ cat /proc/partitions major minor #blocks name 8 0 78125000 sda 8 1 74894998 sda1 8 2 1 sda2 8 5 3229033 sda5 8 16 199148544 sdb <-- could be my drive? but it's not listed under fdisk -l $ fdisk -l Disk /dev/sda: 80.0 GB, 80000000000 bytes 255 heads, 63 sectors/track, 9726 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xd0f4738c Device Boot Start End Blocks Id System /dev/sda1 * 1 9324 74894998+ 83 Linux /dev/sda2 9325 9726 3229065 5 Extended /dev/sda5 9325 9726 3229033+ 82 Linux swap / Solaris and here is my log of /var/log/messages. with a bunch of weird output, can someone let me know what that weird output is? Mar 3 19:49:40 mala kernel: [687455.112029] usb 1-7: new high speed USB device using ehci_hcd and address 3 Mar 3 19:49:41 mala kernel: [687455.248576] usb 1-7: configuration #1 chosen from 1 choice Mar 3 19:49:41 mala kernel: [687455.267450] Initializing USB Mass Storage driver... Mar 3 19:49:41 mala kernel: [687455.269180] scsi4 : SCSI emulation for USB Mass Storage devices Mar 3 19:49:41 mala kernel: [687455.269410] usbcore: registered new interface driver usb-storage Mar 3 19:49:41 mala kernel: [687455.269416] USB Mass Storage support registered. Mar 3 19:49:46 mala kernel: [687460.270917] scsi 4:0:0:0: Direct-Access Maxtor 6 Y200P0 YAR4 PQ: 0 ANSI: 2 Mar 3 19:49:46 mala kernel: [687460.271485] sd 4:0:0:0: Attached scsi generic sg2 type 0 Mar 3 19:49:46 mala kernel: [687460.278858] sd 4:0:0:0: [sdb] 398297088 512-byte logical blocks: (203 GB/189 GiB) Mar 3 19:49:46 mala kernel: [687460.280866] sd 4:0:0:0: [sdb] Write Protect is off Mar 3 19:50:16 mala kernel: [687460.283784] sdb: Mar 3 19:50:16 mala kernel: [687491.112020] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:50:47 mala kernel: [687522.120030] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:51:18 mala kernel: [687553.112034] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:51:49 mala kernel: [687584.116025] usb 1-7: reset high speed USB device using ehci_hcd and address 3 Mar 3 19:52:02 mala kernel: [687596.170632] type=1505 audit(1267671122.035:31): operation="profile_replace" pid=8426 name=/usr/lib/cups/backend/cups-pdf Mar 3 19:52:02 mala kernel: [687596.171551] type=1505 audit(1267671122.035:32): operation="profile_replace" pid=8426 name=/usr/sbin/cupsd Mar 3 19:52:06 mala kernel: [687600.908056] async/0 D c08145c0 0 7655 2 0x00000000 Mar 3 19:52:06 mala kernel: [687600.908062] e5601d38 00000046 e5774000 c08145c0 e4c2a848 c08145c0 d203973a 0002713d Mar 3 19:52:06 mala kernel: [687600.908072] c08145c0 c08145c0 e4c2a848 c08145c0 00000000 0002713d c08145c0 f0a98c00 Mar 3 19:52:06 mala kernel: [687600.908079] e4c2a5b0 c20125c0 00000002 e5601d80 e5601d44 c056f3be e5601d78 e5601d4c Mar 3 19:52:06 mala kernel: [687600.908087] Call Trace: Mar 3 19:52:06 mala kernel: [687600.908099] [<c056f3be>] io_schedule+0x1e/0x30 Mar 3 19:52:06 mala kernel: [687600.908107] [<c01b2cf5>] sync_page+0x35/0x40 Mar 3 19:52:06 mala kernel: [687600.908111] [<c056f8f7>] __wait_on_bit_lock+0x47/0x90 Mar 3 19:52:06 mala kernel: [687600.908115] [<c01b2cc0>] ? sync_page+0x0/0x40 Mar 3 19:52:06 mala kernel: [687600.908121] [<c020f390>] ? blkdev_readpage+0x0/0x20 Mar 3 19:52:06 mala kernel: [687600.908125] [<c01b2ca9>] __lock_page+0x79/0x80 Mar 3 19:52:06 mala kernel: [687600.908130] [<c015c130>] ? wake_bit_function+0x0/0x50 Mar 3 19:52:06 mala kernel: [687600.908135] [<c01b459f>] read_cache_page_async+0xbf/0xd0 Mar 3 19:52:06 mala kernel: [687600.908139] [<c01b45c2>] read_cache_page+0x12/0x60 Mar 3 19:52:06 mala kernel: [687600.908144] [<c0232dca>] read_dev_sector+0x3a/0x80 Mar 3 19:52:06 mala kernel: [687600.908148] [<c0233d3e>] adfspart_check_ICS+0x1e/0x160 Mar 3 19:52:06 mala kernel: [687600.908152] [<c023339f>] ? disk_name+0xaf/0xc0 Mar 3 19:52:06 mala kernel: [687600.908157] [<c0233d20>] ? adfspart_check_ICS+0x0/0x160 Mar 3 19:52:06 mala kernel: [687600.908161] [<c02334de>] check_partition+0x10e/0x180 Mar 3 19:52:06 mala kernel: [687600.908165] [<c02335f6>] rescan_partitions+0xa6/0x330 Mar 3 19:52:06 mala kernel: [687600.908171] [<c0312472>] ? kobject_get+0x12/0x20 Mar 3 19:52:06 mala kernel: [687600.908175] [<c0312472>] ? kobject_get+0x12/0x20 Mar 3 19:52:06 mala kernel: [687600.908180] [<c039fc43>] ? get_device+0x13/0x20 Mar 3 19:52:06 mala kernel: [687600.908185] [<c03c263f>] ? sd_open+0x5f/0x1b0 Mar 3 19:52:06 mala kernel: [687600.908189] [<c020fda0>] __blkdev_get+0x140/0x310 Mar 3 19:52:06 mala kernel: [687600.908194] [<c020f0ac>] ? bdget+0xec/0x100 Mar 3 19:52:06 mala kernel: [687600.908198] [<c020ff7a>] blkdev_get+0xa/0x10 Mar 3 19:52:06 mala kernel: [687600.908202] [<c0232f30>] register_disk+0x120/0x140 Mar 3 19:52:06 mala kernel: [687600.908207] [<c0308b4d>] ? blk_register_region+0x2d/0x40 Mar 3 19:52:06 mala kernel: [687600.908211] [<c03084f0>] ? exact_match+0x0/0x10 Mar 3 19:52:06 mala kernel: [687600.908216] [<c0308cf0>] add_disk+0x80/0x140 Mar 3 19:52:06 mala kernel: [687600.908221] [<c03084f0>] ? exact_match+0x0/0x10 Mar 3 19:52:06 mala kernel: [687600.908225] [<c0308860>] ? exact_lock+0x0/0x20 Mar 3 19:52:06 mala kernel: [687600.908230] [<c03c53df>] sd_probe_async+0xff/0x1c0

  Read the article

• What are the best options for a root filesystem hosted on SSD under Linux

  - by stsquad

  I'm working on an embedded system which is going to be booting and hosting it's rootfs on an SSD disk. We are currently looking at using Intel X-18M SSDs. The file system structure will have a fairly static /usr section (modulo software upgrades) and an active /var and /var/log for maintaining state and logging. Given the wear-levelling done by the underlying flash does having separate partitions help or hinder? As modern SSDs appear as straight block devices and hide their mapping magic behind their firmware is there any point trying to optimise the choice of file-system that sits on-top of the SSD? Finally does enable SMART monitoring make any sense in this context or are their SSD specific ways of determining the underlying health of the storage hardware?

  Read the article

< Previous Page | 56 57 58 59 60 61 62 63 64 65 66 67  | Next Page >