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• Proliant RAID 1 Rebuild Questions

  - by Nicholas

  I have a HP Proliant ML350 G5 server that experienced a power supply failure overnight. The power supply was replaced but unfortunately it got restarted with only 1 disk in the RAID 1 set plugged in. (The raid controller is the build in E200i). The raid BIOS then said on start-up that it had entered Interim Recovery Mode. However I would have expected it to still start up with only the 1 drive. The bios however says that it cannot find a C: drive and enters a reboot loop polling the other boot devices. First question is, is this normal behaviour not to start up on 1 disk? The second drive was then plugged in (all drives are ok) and the raid bios started an automatic rebuild on that disk. This appears to be a background process as there is no progress shown. However based on the light flashing it looks like it is working. My second question is how long will this rebuild take? (36GB 15K SAS drive). I cannot see any error messages and it looks like it is rebuilding the drive ok, but the computer still will not start-up. It still says during the boot up process that the C: drive is not found. If I wait for the rebuild to finish, is it likely to fix itself and find the C: drive? Or is there some other problem here?

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• Why does my dd backup of MacBook OS X fail to boot upon restore?

  - by James

  I created a backup of a MacBook hard drive (WD2500BEVS-88US) by hooking it up as a secondary drive on my linux system (Ubuntu 10.10). I used the following command: sudo dd if=/dev/sdc of=/home/backup.img bs=2M This appears to have completed with no errors. I noticed that the file is only 68 GB in size even though the drive is 250 GB in capacity. I restored the image to a spare drive (WD2500BEVS) with the following command: sudo dd if=/home/backup.img of=/dev/sdb bs=2M When I boot the spare drive in the Mac, it appears to start up for a few seconds and then shuts down. (It does not appear to load into the OS at all). When I open up the drive that won't boot in GParted, it looks like this: When looking at the information for the middle partition with the little red exclamation mark, it shows this: The original hard drive that boots ok shows up like this: Further info on both drives: sudo fdisk -l Disk /dev/sdb: 250.1 GB, 250059350016 bytes 255 heads, 63 sectors/track, 30401 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdb1 1 30402 244198580 ee GPT WARNING: GPT (GUID Partition Table) detected on '/dev/sdc'! The util fdisk doesn't support GPT. Use GNU Parted. Disk /dev/sdc: 250.1 GB, 250059350016 bytes 255 heads, 63 sectors/track, 30401 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdc1 1 30402 244198580 ee GPT So why is my backup or restore failing? Why is dd not creating a byte for byte duplicate?

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• Backup, Migrate or Clone Failing CentOS 4 (LVM)

  - by Hegelworm

  Hello there, I've been running a BlueQuartz CentOS 4 system (Nuonce.net distro) for a few years now and although the hard drive (Deskstar) has always been a bit noisy, on a few recent occasions I've heard it having trouble spinning up. Basically, I want to clone this drive to a similar sized one (80 Gig). I've spent many hours reading upon dd, dd_rescue, rsync, clonezilla and LVM mirroring yet the sheer number of options and nightmarish accounts has left me frozen - unable to make an informed decision as to how to start. I've made a few attempts. dd failed after about 2 hours, as, although the drives appeared to be identical on the surface (ATA Seagate Barracudas, Thai not Chinese), the destination drive is slightly smaller. My most recent attempt involved using a Debian CD to format the new drive and then rsync-ing everything over and editing the new drive's grub and fstab to reflect the changes. No joy here either as I hadn't chosen LVM when partitioning the destination drive and it wouldn't boot. As you can probably tell, I'm out of my depth here and a panic-invoking mixture of caution and frustration has prompted me to sign up here. The server itself, although not strictly a production environment, has a very specific installation of Festival, LAME and ffMpeg and provides the back-end for a Text-to-Speech jQuery plugin that I've built over the last 2 years. I'm also planning to rebuild the whole TTS system on Debian as the existing CentOS system still has PHP4 etc. For now though, I'd really like to just shift everything over to a new drive. As this is my first post, please feel free to lay any house rules on me that I might've overlooked; I've been hovering around StackOverflow for a while now but have only just signed up. Many thanks.

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• Why are folders disappearing in Windows XP?

  - by XenoFoxx

  I am researching a problem for a friend, and unfortunatly do not have direct access to his computer. I've tried to gather as much information as possible and I have researched it on various websites. I've not found anyone having the same problem my friend is having. So here goes: He has a media server in his home running Microsoft Windows XP. It has 3 drives, 1 for the OS and 2 for mass storage. Not long ago he went to access one of the mass storage media drives and it was empty, except for a single folder. His first assumption was that his roommate had deleted everything on the drive (excluding the remaining folder). He then checked the properties of the drive and it was still saying that the hard drive was nearly full. I told him to check the recycling bin, thinking that whoever deleted them didn't clear them from recycling and that they were still taking up space on the drive. My friend said the recycling bin was empty. So we have a drive that the Windows file management system says is empty (again except for the remaining folder), but the properties of the drive say it's mostly full. Now it gets weirder My friend tried to create a new folder on this drive and it auto-named itself "New Folder(1)" which means that it recognizes there is already a "New Folder" in that directory. He tried to rename it to a name that he KNEW was there previsouly, and Windows wouldn't allow it because it was a duplicate folder name. SO now it seems the folders are there, but not displaying in Windows Explorer. Both of us have no idea why this is occuring, why the folders vanished, why the one remaining folder didn't vanish, or how to make them visable again. Anyone else ever experience this? I can get more details if needed.

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• how to initialize two logical drives on a HP P400i controller without reboot

  - by John

  What I am trying to do is initialize two logical drives on a HP P400i embedded controller without a reboot of the system here my current Array config: array A (SAS, Unused Space: 0 MB) logicaldrive 1 (17.9 GB, RAID 5, OK) logicaldrive 2 (17.9 GB, RAID 5, OK) logicaldrive 3 (75.9 GB, RAID 5, OK) logicaldrive 4 (25.0 GB, RAID 5, OK) physicaldrive 1I:1:1 (port 1I:box 1:bay 1, SAS, 72 GB, OK) physicaldrive 1I:1:2 (port 1I:box 1:bay 2, SAS, 72 GB, OK) physicaldrive 1I:1:3 (port 1I:box 1:bay 3, SAS, 72 GB, OK) array B (SAS, Unused Space: 0 MB) logicaldrive 5 (99 MB, RAID 0, OK) logicaldrive 6 (68.2 GB, RAID 0, OK) physicaldrive 1I:1:4 (port 1I:box 1:bay 4, SAS, 72 GB, OK) windows 2003 machine running the HpCISs2.sys driver version 6.20.0.32 . I have the ACU and ACU CLI tools installed version 8.28.13.0, P400i firmware version 2.74 . Now what I'd like to do is removes the physical drive 1I:1:4 and delete the two logical drives in array B. then insert a new drive in to bay 4 that contains two new logical drives and have them show up in array B again. So far after I remove the drive and delete the failed logical drives, I insert the new drive and run HPacucli rescan. I get the new drive to show up as unassinged physical drive but I cant figure out now to "for lack of a better word" mount the 2 logical drives on the new unassinged disk. If I reboot the system the array controller picks up the new fourth drive and creates Array B with the drives without problem but I'd really like to not have to reboot the server. Any ideas?

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• Unable to write DVD-R(Blank DVD's)

  - by FrozenKing

  I have a problem in dvd drive i.e. It can read CD/DVD and can write CD and all CD/DVD-RW but cannot write DVD DVD drive model is SH-S203B Samsung; I also have a log file created by nero burning rom 11. Actually the fact is no Blank DVD's are being read in my dvd drive only previously written dvd's can be read! Is this the problem of OS or should I try cleaning the dvd drive or my DVD drive is 4yrs old so is it going to spoil now, since it is showing this type of symptoms! OS = WinXP AV = KIS 2012 DVD Drive = Samsung SH-S203B (Also tried latest firmware and downgrade versions also) IA32 Nero Version: 11.2.4.100 Internal Version: 11,2,4,100 Recorder: <TSSTcorp CDDVDW SH-S203B>Version: SB04 - HA 1 TA 0 - 11.2.4.100 Adapter driver: <Serial ATA> HA 1 Drive buffer : 2048kB Bus Type : via Inquiry data CD-ROM: <TSSTcorp CDDVDW SH-S203B >Version: SB04 - HA 1 TA 0 - 11.2.4.100 Adapter driver: <Serial ATA> HA 1 18:58:10 #37 SPTI -1511 File SCSIPassThrough.cpp, Line 224 CdRom0: SCSIStatus(x02) WinError(0) NeroError(-1511) CDB Data: 0x28 00 00 00 00 00 00 00 10 00 Sense Key: 0x04 (KEY_HARDWARE_ERROR) Sense Code: 0x3E Sense Qual: 0x02 Sense Area: 0x70 00 04 00 00 00 00 0A 00 00 00 00 3E 02 Buffer x08047340: Len x8000 18:58:10 #38 SectorVerify 20 File Cdrdrv.cpp, Line 12057 Read errors from sector 0 to 14 <Padding> 18:58:19 #39 SPTI -1511 File SCSIPassThrough.cpp, Line 224 CdRom0: SCSIStatus(x02) WinError(0) NeroError(-1511) CDB Data: 0x28 00 00 00 00 10 00 00 10 00 Sense Key: 0x04 (KEY_HARDWARE_ERROR) Sense Code: 0x3E Sense Qual: 0x02 Sense Area: 0x70 00 04 00 00 00 00 0A 00 00 00 00 3E 02 Buffer x08047340: Len x8000 18:58:19 #40 SectorVerify 21 File Cdrdrv.cpp, Line 12057 Read error at sector 15 <Virtual Multisession Info> 18:58:19 #41 SectorVerify 20 File Cdrdrv.cpp, Line 12057 Read errors from sector 16 to 18 <Volume Structure Descriptor Sequence> 18:58:28 #42 SPTI -1511 File SCSIPassThrough.cpp, Line 224 CdRom0: SCSIStatus(x02) WinError(0) NeroError(-1511) CDB Data: 0x28 00 00 00 00 20 00 00 10 00 Sense Key: 0x04 (KEY_HARDWARE_ERROR) Sense Code: 0x3E Sense Qual: 0x02 Sense Area: 0x70 00 04 00 00 00 00 0A 00 00 00 00 3E 02 Buffer x08047340: Len x8000

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• Recover data from a Thecus N4100 NAS jbod partition

  - by TimothyP

  I have a Thecus N4100 NAS wich had a 2TB drive in it configured as jbod partition. Later I tried adding a second drive to expand the available space. I added it to the jbod configuration but I did not get any extra space. Then I tried removing the second drive but then the NAS system indicated the jbod configuration was damaged. After a reboot it told me there is no configuration and I need to create a new RAID/jbod configuration and that I would lose all data on the drive. Of course I did not do this, I took the 2TB drive and checked with Linux if the partition was still there and it is... completely intact. I found that linux recognizes it as a /dev/mdX device and that I should be able to mount it but I don't know the file system type. Anyway.... is there a way to recover the data? Since everything has always been on a single drive it should all be there right? I can connect the drive to Windows , Linux or MacOS so whatever gets the job done.

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• WS2008 subst in Logon script does not "stick"

  - by Frans

  I have a terminal server environment exclusively with Windows Server 2008. My problem is that I need to "map" a drive letter to each users Temp folder. This is due to a legacy app that requries a separate Temp folder for each user but which does not understand %temp%. So, just add "subst t: %temp%" to the logon script, right? The problem is that, even though the command runs, the subst doesn't "stick" and the user doesn't get a T: drive. Here is what I have tried; The simplest version: 'Mapping a temp drive Set WinShell = WScript.CreateObject("WScript.Shell") WinShell.Run "subst T: %temp%", 2, True That didn't work, so tried this for more debug information: 'Mapping a temp drive Set WinShell = WScript.CreateObject("WScript.Shell") Set procEnv = WinShell.Environment("Process") wscript.echo(procEnv("TEMP")) tempDir = procEnv("TEMP") WinShell.Run "subst T: " & tempDir, 3, True This shows me the correct temp path when the user logs in - but still no T: Drive. Decided to resort to brute force and put this in my login script: 'Mapping a temp drive Set WinShell = WScript.CreateObject("WScript.Shell") WinShell.Run "\\domain\sysvol\esl.hosted\scripts\tempdir.cmd", 3, True where \domain\sysvol\esl.hosted\scripts\tempdir.cmd has this content: echo on subst t: %temp% pause When I log in with the above then the command window opens up and I can see the subst command being executed correctly, with the correct path. But still no T: drive. I have tried running all of the above scripts outside of a login script and they always work perfectly - this problem only occurs when doing it from inside a login script. I found a passing reference on an MSFN forum about a similar problem when the user is already logged on to another machine - but I have this problem even without being logged on to another machine. Any suggestion on how to overcome this will be much appreciated.

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• How to access previous VHD versions of system backup?

  - by feklee

  Quote from the 31 Oct 2009 TechNet article "Learn more about system image backup": During the first backup, the backup engine scans the source drive and copies only blocks that contain data into a .vhd file stored on the target, creating a compact view of the source drive. The next time a system image is created, only new and changed data is written to the .vhd file, and old data on the same block is moved out of the VHD and into the shadow copy storage area. Volume Shadow Copy Service is used to compute the changed data between backups, as well as to handle the process of moving the old data out to the shadow copy area on the target. This approach makes the backup fast (since only changed blocks are backed up) and efficient (since data is stored in a compact manner). When restoring the image, blocks will be restored to their original locations on the source disk. If you want to restore from an older backup, the engine reads from the shadow copy area and restores the appropriate blocks. For the last days, a daily system backup of drive C: to drive E: has been scheduled and run by Windows 7 Backup and Restore. Drive C: currently holds 233 GB of data, which fits comfortably on drive E:, a 1 TB drive, with 727 GB of free space remaining. How do I access the previous version of a VHD? I right clicked on files and folders in E:\WindowsImageBackup, and I looked for Previous Versions but always: There are no previous versions available

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• How to migrate Outlook Express mail rules?

  - by ronwest

  I have a home computer that only had a 15Gb C: drive, and ran out of space with all the Microsoft Updates, etc, that keep coming down. So I fitted a 160Gb drive as a C: drive and altered the drive jumpers to make the old C: drive into a slave D: drive, to save migrating documents, etc. I've installed a clean copy of Windows XP SP3 and reassigned the new Outlook Express' mailstore path to point to the old mailstore folder that now has a D: drive letter - and it all works OK. However, my extensive list of mail rules have not been transferred to the new OE and I have not been able to identify how they are stored. To find it I added a new rule to the new OE, exited OE, then searched on the whole computer (including hidden/system files) for files altered around the time I added the rule. I hoped I could just overwrite a new empty file with an old one. But the only files that seem to be changed are Windows system-level files and some bits and pieces in the Windows\PreFetch sub-folder. None of them can be opened as XP has them locked, and none of them have names that are anything to do with email or rules. Does anyone know of any way of migrating OE rules, or do I have to re-enter them by hand? Thanks!

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• Windows XP Disappearing Folders

  - by XenoFoxx

  I am researching a problem for a friend, and unfortunatly do not have direct access to his computer. I've tried to gather as much information as possible and I have researched it on various websites. I've not found anyone having the same problem my friend is having. So here goes: He has a media server in his home running Microsoft Windows XP. It has 3 drives, 1 for the OS and 2 for mass storage. Not long ago he went to access one of the mass storage media drives and it was empty, except for a single folder. His first assumption was that his roommate had deleted everything on the drive (excluding the remaining folder). He then checked the properties of the drive and it was still saying that the hard drive was nearly full. I told him to check the recycling bin, thinking that whoever deleted them didn't clear them from recycling and that they were still taking up space on the drive. My friend said the recycling bin was empty. So we have a drive that the windows file management system says is empty (again except for the remaining folder), but the properties of the drive say it's mostly full. Now it gets weirder My friend tried to create a new folder on this drive and it auto-named itself "New Folder(1)" which means that it recognizes there is already a "New Folder" in that directory. He tried to rename it to a name that he KNEW was there previsouly, and windows wouldn't allow it because it was a duplicate folder name. SO now it seems the folders are there, but not displaying in Windows Explorer. Both of us have no idea why this is occuring, why the folders vanished, why the one remaining folder didn't vanish, or how to make them visable again. Anyone else ever experience this? I can get more details if needed.

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• Un-do Windows disk convert HFS+

  - by BLAKE

  Last night, a friend asked my to give him a copy of a word document. He handed me an external hard drive and left. I plugged the hard drive into my file server running Windows Server 2003, opened disk management and clicked OK. (I know that in Windows 2003 you need to manually assign a drive letter to external drives.) I then looked at the drive in disk management and it said that it was unallocated space. I called my friend and he said that there was data on the drive, but he used it with his Mac Book. Aperantly when I clicked OK in disk management I converted the from HFS+ file system to something else. Is there any way to undo the disk convert? I immediately removed the drive, so there was no writing to it. Windows did not format the drive, it just converted it. Is the data still there? All the data recovery programs I have are for windows, can they read the Mac file system? I need to get the data back, what can I do?

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• Can a non-redundant RAID5 cause any serious problems (compared to RAID0)?

  - by leemes

  I used to have a three-disc RAID5 (mdadm) in my computer for personal media storage (music, videos, photos, programs, games, ...). It had three discs with 750 GB each, resulting in an array capacity of 1.5 TB. One day (one year ago), I needed one of those discs to install another operating system. I thought, I don't need the redundancy anymore since I backup the most important stuff (personal photos e.g.) on an external disc anyway. So I decided to remove one of the three discs without converting the RAID to RAID0 or even two separate discs, because I had no temporary storage (since one cannot simply convert the RAID5 to RAID0 AFAIK). So now, for about one year, I have a non-redundant RAID5 with 2 of 3 discs running. Sometimes, one of the discs has a defective contact at the power cable or something similar causing the drive to stop working temporarily (I don't know exactly what it is). Since it still works when rebooting the computer and in most cases by calling some mdadm commands, it wasn't that problematic. Note that the data is not very critical, since I still have a backup of the most important stuff. But in the last few weeks, one of the drives fails very frequently (every few hours), so it gets really annoying to manage this. My questions are: Is there any disadvantage (apart from the annoying management) of a non-redundant RAID5 (with one drive less than typical) over a RAID0? If I understand it correctly, both have no redundancy and the same capacity. On a temporary drive failure, I can restart the array in both cases, assuming that the drive itself still works after the failure. Can it happen that the drive contents alter on a drive failure, making the array inconsistent? If so, can I tell mdadm to check the array for failures (without a file system level checking tool)? Since the drive most probably only has a defective contact causing it to fail for a second only, can I tell mdadm to automatically restart the array, so I will not even notice the failure if no application wanted to access the file system during the failure?

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• Computer will not boot - disk read error - cannot boot from HD or DVD

  - by Grant Palin

  This is a 3 year-old system: HP a1640n. There have been no issues with it in the past. I added a video card 2 years ago, and more memory 1 year ago, both without issues. There haven't been any recent hardware changes. I did install Win7 in Oct., but there were no issues with that either. I used the computer fine two nights ago, and turned it off. Yesterday, I tried to turn it on, and got the error: "A Disk Read Error Occurred. Press CTRL ALT DEL to restart" So I restart, see the initial start screen (HP) and enter the BIOS. The hard drive and dvd drive appear to be listed, but the names are gibberish text. I tried putting a Windows disk in the dvd drive, and continued with the boot, but the disk did not get recognized. Even though the BIOS was set to check for optical media before the hard drive. Back to the error screen. If the computer would boot from a cd or dvd, I would just figure the hard drive needed replacing. But both being problematic worries me. Is this a matter of replacing both the hard drive and dvd drive, or might it be an indication of a bigger problem? Thanks for any advice.

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• Un-do Windows disk convert HFS+

  - by BLAKE

  Last night, a friend asked my to give him a copy of a word document. He handed me an external hard drive and left. I plugged the hard drive into my file server running Windows Server 2003, opened disk management and clicked OK. (I know that in Windows 2003 you need to manually assign a drive letter to external drives.) I then looked at the drive in disk management and it said that it was unallocated space. I called my friend and he said that there was data on the drive, but he used it with his Mac Book. Aperantly when I clicked OK in disk management I converted the from HFS+ file system to something else. Is there any way to undo the disk convert? I immediately removed the drive, so there was no writing to it. Windows did not format the drive, it just converted it. Is the data still there? All the data recovery programs I have are for windows, can they read the Mac file system? I need to get the data back, what can I do?

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• regular expression repeating subexpression

  - by Michael Z

  I have the following text <pattern name="pattern1"/> <success>success case 1</success> <failed> failure 1</failed> <failed> failure 2</failed> <unknown> unknown </unknown> <pattern name="pattern2"/> <success>success case 2</success> <otherTag>There are many other tags.</otherTag> <failed> failure 3</failed> And the regular expression <failed>[\w|\W]*?</failed> matches all the lines contains failed tag. What do I need to to if I want to include the lines contains pattern tag as well? Basically, I want the following output: <pattern name="pattern1"/> <failed> failure 1</failed> <failed> failure 2</failed> <pattern name="pattern2"/> <failed> failure 3</failed> I am doing this in javascript, I do not mind of doing some intermediate steps.

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• How to get markers after calling drive directions in Google Maps API?

  - by Ivan Rocha

  Hi all, I just started working using Google Maps API yesterday, and trying to set up drive directions to my map. My problem is: when I call the function load, [...] gdir = new GDirections(map, directionsPanel); [...] gdir.load("from: " + fromAddress + " to: " + toAddress); it returns a map whose markers are not draggable. So, I need to make them draggable in order to recalculate the directions, but I can't get the markers objects. Someone knows how can I do it? Thanks, Ivan.

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• How do I load the Oracle schema into memory instead of the hard drive?

  - by Andrew

  I have a certain web application that makes upwards of ~100 updates to an Oracle database in succession. This can take anywhere from 3-5 minutes, which sometimes causes the webpage to time out. A re-design of the application is scheduled soon but someone told me that there is a way to configure a "loader file" which loads the schema into memory and runs the transactions there instead of on the hard drive, supposedly improving speed by several orders of magnitude. I have tried to research this "loader file" but all I can find is information about the SQL* bulk data loader. Does anyone know what he's talking about? Is this really possible and is it a feasible quick fix or should I just wait until the application is re-designed?

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• namespace extension.. galaxy file system toolkit...gmail shell drive like utility...

  - by Muhammad Adnan

  i was looking for some namespace extention to extend using c# (.net) but didn't find much help online except Galaxy Filesystem tooklkit. which are vc++ based but comes with c# and java wrapper classes... which helps me alot to start and i did. i have extended that enough now and made installer to install. it get installed successfully but don't know why, when i open it, system get stuck... :( i thought my modified version might have some problem so i tried to run Galaxy filesystem toolkit's author original version and it responded in same way as mine do :D :( now feeling bit helpless as even author is not responding my queries regarding my queries for some reason... any help would be really appreciated.... FYI: i need to have Gmail drive like stuff...

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• Using the windows api and C++, how could I load an exe from the hard drive and run it in its own thread?

  - by returneax

  For the sake of learning I'm trying to do what the OS does when launching a program ie. parsing a PE file and giving it a thread of execution. If I have two exe's one called foo.exe and the other bar.exe, how could I have foo.exe load the contents of bar.exe into memory then have it execute from there in its own thread? I know how to get it into memory using MapViewOfFile or by simple loading the contents on the hard drive into a buffer. I'm assuming simply copying the contents of bar.exe on disk into its own suspended thread and running it wouldn't work. I am semi-familiar with PE file internals. All help is very much appreciated, of course :)

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• Library to fake intermittent failures according to tester-defined policy?

  - by crosstalk

  I'm looking for a library that I can use to help mock a program component that works only intermittently - usually, it works fine, but sometimes it fails. For example, suppose I need to read data from a file, and my program has to avoid crashing or hanging when a read fails due to a disk head crash. I'd like to model that by having a mock data reader function that returns mock data 90% of the time, but hangs or returns garbage otherwise. Or, if I'm stress-testing my full program, I could turn on debugging code in my real data reader module to make it return real data 90% of the time and hang otherwise. Now, obviously, in this particular example I could just code up my mock manually to test against a random() routine. However, I was looking for a system that allows implementing any failure policy I want, including: Fail randomly 10% of the time Succeed 10 times, fail 4 times, repeat Fail semi-randomly, such that one failure tends to be followed by a burst of more failures Any policy the tester wants to define Furthermore, I'd like to be able to change the failure policy at runtime, using either code internal to the program under test, or external knobs or switches (though the latter can be implemented with the former). In pig-Java, I'd envision a FailureFaker interface like so: interface FailureFaker { /** Return true if and only if the mocked operation succeeded. Implementors should override this method with versions consistent with their failure policy. */ public boolean attempt(); } And each failure policy would be a class implementing FailureFaker; for example there would be a PatternFailureFaker that would succeed N times, then fail M times, then repeat, and a AlwaysFailFailureFaker that I'd use temporarily when I need to simulate, say, someone removing the external hard drive my data was on. The policy could then be used (and changed) in my mock object code like so: class MyMockComponent { FailureFaker faker; public void doSomething() { if (faker.attempt()) { // ... } else { throw new RuntimeException(); } } void setFailurePolicy (FailureFaker policy) { this.faker = policy; } } Now, this seems like something that would be part of a mocking library, so I wouldn't be surprised if it's been done before. (In fact, I got the idea from Steve Maguire's Writing Solid Code, where he discusses this exact idea on pages 228-231, saying that such facilities were common in Microsoft code of that early-90's era.) However, I'm only familiar with EasyMock and jMockit for Java, and neither AFAIK have this function, or something similar with different syntax. Hence, the question: Do such libraries as I've described above exist? If they do, where have you found them useful? If you haven't found them useful, why not?

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• What layer to introduce human readable error messages?

  - by MrLane

  One of the things that I have never been happy with on any project I have worked on over the years and have really not been able to resolve myself is exactly at what tier in an application should human readable error information be retrieved for display to a user. A common approach that has worked well has been to return strongly typed/concrete "result objects" from the methods on the public surface of the business tier/API. A method on the interface may be: public ClearUserAccountsResult ClearUserAccounts(ClearUserAccountsParam param); And the result class implementation: public class ClearUserAccountsResult : IResult { public readonly List<Account> ClearedAccounts{get; set;} public readonly bool Success {get; set;} // Implements IResult public readonly string Message{get; set;} // Implements IResult, human readable // Constructor implemented here to set readonly properties... } This works great when the API needs to be exposed over WCF as the result object can be serialized. Again this is only done on the public surface of the API/business tier. The error message can also be looked up from the database, which means it can be changed and localized. However, it has always been suspect to me, this idea of returning human readable information from the business tier like this, partly because what constitutes the public surface of the API may change over time...and it may be the case that the API will need to be reused by other API components in the future that do not need the human readable string messages (and looking them up from a database would be an expensive waste). I am thinking a better approach is to keep the business objects free from such result objects and keep them simple and then retrieve human readable error strings somewhere closer to the UI layer or only in the UI itself, but I have two problems here: 1) The UI may be a remote client (Winforms/WPF/Silverlight) or an ASP.NET web application hosted on another server. In these cases the UI will have to fetch the error strings from the server. 2) Often there are multiple legitimate modes of failure. If the business tier becomes so vague and generic in the way it returns errors there may not be enough information exposed publicly to tell what the error actually was: i.e: if a method has 3 modes of legitimate failure but returns a boolean to indicate failure, you cannot work out what the appropriate message to display to the user should be. I have thought about using failure enums as a substitute, they can indicate a specific error that can be tested for and coded against. This is sometimes useful within the business tier itself as a way of passing via method returns the specifics of a failure rather than just a boolean, but it is not so good for serialization scenarios. Is there a well worn pattern for this? What do people think? Thanks.

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• Understanding Windows 8 Recovery options

  - by stuffe

  Background: I am preparing a PC that I am sending to a relative abroad, who has little or no internet access, and next to no sensible options for getting IT support should anything go wrong. As such I am trying to provide a full set of recovery options such that they are able to reinstall the OS with minimum fuss or assistance if required. The PC is a brand new Acer laptop that came with Windows 7 pre-installed (and an associated recovery partition) and a free upgrade to Windows 8. I have installed Windows 8 from scratch performing a format and clean install from media I burned from the official download. The existing Windows 7 recovery partition is still there, and I can still boot from it. I have created recovery DVDs of that in case it is ever lost. Here are my recovery options so far. I can perform a factory reset of Win 7 via the recovery partition I can perform a factory reset of Win 7 via burned recovery DVDs I can re-install Windows 8 cleanly from a DVD All of these are useful, but not what I want, because the first 2 methods use Win 7, and still fill the machine with crapware, and the latter doesn't provide for any post-install customisation and software installation. So, I am looking to see what other options are available to perform a Windows 8 recovery that will be more than a simple install. I am aware that Win8 comes with some useful refresh tools: Refresh your PC - Re-install Win 8 over the top of your existing installation, recovering from any Windows corruption etc. I can run this from my current install, although it says some files are missing that will be provided by me install or recovery media, which seems to be code for stick your install DVD in, and it starts after I do that - unfortunately for this particular laptop you need to specify a particular WIFI driver or the install bombs out part way through with IRQL errors, and this refresh method skips the part where you can load a driver, so it's no use to me. I think I can fix this by creating a custom recovery image using the recimg.exe command but it takes hours to complete so I haven't tried it yet. Reset your PC - Perform a full install and lose all your files. Again it needs my Install media inserting before it will do anything, but then it provides an error (will include later when I recreate it...) Now, these recovery options look useful (in principal, although both are fail for me) but they rely on having a working system to access the tools, which leads me to the last option, of making a Recovery USB drive. I have made a recovery drive, and it should perform loads of useful things, including copying my WIN7 recovery partition to the drive, providing the above refresh and reset options, providing other troubleshooting options and also the ability to restore from a custom image, only none of them seem to work for me. Creating the Recovery Drive - the option to include my recovery partition is greyed out. The partition exists and works fine, why will it not copy it? Refresh - I imagine this would have the same issues as I described before, but this is moot because when I try it says that the "drive where Windows is installed is locked, please unlock the drive and try again" with no info on what that means and how to do it. Restore - Again, probably pointless as I can just use the DVD, but it also errors: "unable to reset your PC. A required drive partition is missing" System Restore - should let me roll back a bad driver etc as per normal in Windows, only it simply says "To use system restore you must specify which windows installation to restore. Restart this computer, select an operating system, and select system restore" ?!?! System Image Recovery - this seems to be offering to restore from a Windows system image, but this is deprecated in Windows 8, although you can still make one if you use the Windows 7 Backup tools, however the resultant file is too large to put on the USB stick as it's FAT formatted, and would be a massive stack of DVDs anyway. So useless. It would be nice it it would work with the custom recovery image you can use with the refresh command, but there seems no option to do this. Automatic Repair - some diagnostics, which seem useless as it happily tells me it can't fix my problem, even though I have none. Command Prompt - yay, this works! What on earth do I want to use it for... Had any of the above worked, it might be useful, but as any form of install still requires you to have the DVD, and any form of custom recovery image also requires you to have either a massive stack of DVDs or an NTFS formatted backup device in addition to the recovery drive, it sort of ruins the point. It doesn't seem rocket science. I want to create a bootable USB drive that I can refresh Windows over an existing install with, perform a clean reinstall to a bare system, or recovery a customised image with existing apps installed. If anyone can point me in a direction that allows me to make a single recovery drive do these all these things, I would appreciate it. I have a 32Gb USB3 thumb drive that I bought for this very purpose, but it's seems to be fighting to let me do anything useful. At this rate I will be making a DriveImageXML recovery stick and dumping the OS with that, which I know works, but isn't so elegant as using the proper tools..

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• Does a hard drive "working hard", i.e. when defragmenting or otherwise continuously active, significantly affect a laptop's temperature?

  - by Marko

  Trying to diagnose and fix an overheating Acer 5735 laptop, running speedfan and doing general workload to try and cause the overheat conditions. I notice that windows xp is badly fragmented according to defraggler, at 58% fragmentation. So I defrag whilst watching the speedfan window, which was at the start reporting high warning style symbols for all of the sensors. After the defrag, I rebooted and ran a few programs, and even defraggler again and the sensors in speedfan all reported green i.e. not high. Wondering if there is a correlation between windows fragmentation causing the hard drive to work harder and produce more heat inside the laptop? dont want to just assume that the problems are resolved, so either speedfan is not accurate enough or fragmentation can lead to additional hard drive heat? All comments or suggestions welcome.

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• How do I image my hard drive for backup? Or do I just need to backup the files?

  - by NoCatharsis

  I have never imaged a hard drive, so I don't know what software to use or how to prepare my system for imaging. Is this the best way to backup? In the past, I've always just kept a copy of my important files on an external drive and in Gmail or DropBox for smaller stuff, but it would be nice to just take one image and restore from that if something ever goes wrong. Thanks for the help. EDIT: I'm sorry, I forgot to mention the OS. I would like to do this for my home and work computers, which are Vista and XP respectively. And actually I'm about to upgrade to Windows 7 at home, so details on that would be appreciated too.

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