Search Results

Search found 14841 results on 594 pages for 'performance monitoring'.

Page 152/594 | < Previous Page | 148 149 150 151 152 153 154 155 156 157 158 159  | Next Page >

• Should I use "Raid 5 + spare" or "Raid 6"?

  - by Trevor Boyd Smith

  What is "Raid 5 + Spare" (excerpt from User Manual, Sect 4.17.2, P.54): RAID5+Spare: RAID 5+Spare is a RAID 5 array in which one disk is used as spare to rebuild the system as soon as a disk fails (Fig. 79). At least four disks are required. If one physical disk fails, the data remains available because it is read from the parity blocks. Data from a failed disk is rebuilt onto the hot spare disk. When a failed disk is replaced, the replacement becomes the new hot spare. No data is lost in the case of a single disk failure, but if a second disk fails before the system can rebuild data to the hot spare, all data in the array will be lost. What is "Raid 6" (excerpt from User Manual, Sect 4.17.2, P.54): RAID6: In RAID 6, data is striped across all disks (minimum of four) and a two parity blocks for each data block (p and q in Fig. 80) is written on the same stripe. If one physical disk fails, the data from the failed disk can be rebuilt onto a replacement disk. This Raid mode can support up to two disk failures with no data loss. RAID 6 provides for faster rebuilding of data from a failed disk. Both "Raid 5 + spare" and "Raid 6" are SO similar ... I can't tell the difference. When would "Raid 5 + Spare" be optimal? And when would "Raid 6" be optimal"? The manual dumbs down the different raid with 5 star ratings. "Raid 5 + Spare" only gets 4 stars but "Raid 6" gets 5 stars. If I were to blindly trust the manual I would conclude that "Raid 6" is always better. Is "Raid 6" always better?

  Read the article

• Where do vendors publish internal transfer rates of HDDs?

  - by red888

  So I've started to dig into storage fundamentals and found that in order to calculate the IOPS of a HDD you need to know the internal transfer rate of the drive (time it takes data to move from the platters to internal disk's cache). I went on newegg and even a few vendor sites and could not find this info published for any HDDs. Is it sometimes called something else? Take this link to a seagate HDD for instance. Nowhere do I see "internal transfer rate", but I do see something called "Sustained Data Rate OD"- is that the same thing? Just so you know where I'm getting this info (Book: "Information Storage and Management Storing, Managing..."): Consider an example with the following specifications provided for a disk: The average seek time is 5 ms in a random I/O environment; therefore, T = 5 ms. Disk rotation speed of 15,000 revolutions per minute or 250 revolutions per second — from which rotational latency (L) can be determined, which is one-half of the time taken for a full rotation or L = (0.5/250 rps expressed in ms). 40 MB/s internal data transfer rate, from which the internal transfer time (X) is derived based on the block size of the I/O — for example, an I/O with a block size of 32 KB; therefore X = 32 KB/40 MB. Consequently, the time taken by the I/O controller to serve an I/O of block size 32 KB is (TS) = 5 ms + (0.5/250) + 32 KB/40 MB = 7.8 ms. Therefore, the maximum number of I/Os serviced per second or IOPS is (1/TS) = 1/(7.8 × 10^-3) = 128 IOPS.

  Read the article

• How to configure an ASUS motherboard.

  - by Absolute0

  I have an ASUS P7P55-M motherboard running with an Intel Core i5-750 processor and 4 GB RAM with 1600 MT/s speed. For some reason the default settings of the motherboard make all the components run at half their optimums. I have switched to the "D.O.C.P." profile and supposedly everything is as it's supposed to be (verified with CPU-Z). There is also an "X.M.P." profile and a manual one. Are either of the DOCP or XMP safe to go with? I wouldn't use the manual mode as I would likely mess something up real bad. XMP seems to be more memory oriented.

  Read the article

• Weblogic Threads Usage

  - by Hila

  I have an application deployed on WebLogic 10.3, which exhibits a strange behavior. I am running a constant (not too high) load on my application (20 concurrent users, running a light activity). The response time is reasonable (well below 100ms after the application stabilizes) Memory consumption seems fine (My application creates a lot of short-living objects, but they are garbaged collected so the overall memory consumption stays under 500 mb). Threads stats seem healthy as well: And yet, after I leave my test running for a while, more and more execute threads ("[ACTIVE] ExecuteThread: '3' for queue: 'weblogic.kernel.Default (self-tuning)'") are created, until eventually the application crashes: This test hasn't been running for a long time (All the new threads that you don't see in the first screenshot were created while I was writing this question), and I've seen much more threads being created. Any idea why these threads are being created?

  Read the article

• Run serveral daemon using python

  - by ylc

  I noticed that serveral daemon invoked python seperately. For example, I have both wicd and ibus daemon running on my machine. Instead of launching a single instance of python, the daemons run with two python instance at the same time in htop: /usr/bin/python2 -O /usr/share/wicd/daemon/monitor.py python2 /usr/share/ibus/ui/gtk/main.py Is it a waste of doing that? If yes, how can I improve this? If no, why avoid putting all daemons run on a single python instance?

  Read the article

• windows 2000 freezing during large disk write

  - by robert

  We have a windows 2000 sp4 server which freezes up for about 1 minutes while its web-app does a ~500mb write operation. I can see the webapp start to do I/O activity (through process explorer) then the RDP session becomes unresponsive, you can click on windows and buttons but nothing happens. When the disk write finally finishes the session 'catches up' on all the mouse clicks you did during the freeze in a mad flurry of window activity and the server returns to normal. During the freeze the web-app stops as well. The same behaviour happens on the console of the server. (so I know its not a network thing) Nothing appears in the Event logs. Its like nothing happened. I have upgraded all the HP hardware drivers to the latest proliant support pack. And also run a HP hardware diagnostics which found nothing wrong. What would cause a disk write to lock the rest of the OS?

  Read the article

• MySQL Locking Up

  - by Ian

  I've got a innodb table that gets a lot of reads and almost no writes (like, 1 write for every 400,000 reads approx). I'm running into a pretty big problem though when I do INSERT into the table. MySQL completely locks up. It uses 100% cpu, and every single other table (in other databases even) have their statuses set to "Locked" until the INSERT is done. This is a big problem because MySQL stays locked up for up to 4 minutes. I'm using version 5.1.47 (rpm from mysql.com). Any ideas?

  Read the article

• Identify Long Running or Slow PHP Scripts

  - by Kirk

  I have web server that is getting around 25K visits a day up at yougetsignal.com. Sometimes the site feels a bit sluggish. I am hosting it on nginx with php5-fpm. Is there a way for me to see a list of all of the long running requests that are coming to the site? I'd love to have a real-time list of all of the active requests that PHP is handling and how long they have been running. Kind of like top, but just for the web server. This would let me know how long requests are taking and which script is the culprit. Anyone have any ideas on how I can do this?

  Read the article

• Flash stream makes my internet slow and cpu rush

  - by user1225840

  When I try to watch a live Flash stream, my CPU usage goes up to 75% and my Internet speed goes down. If I run a test before the video-stream, my speed is ~40/10Mbps and during the stream it drops to 0.1-0.5Mbps. The stream is laggy and I can only watch one to two seconds at a time, start/stop/start/stop. I have cleared my history, cache, cookies, temp files, and so on. I have searched for malware and took care of that. I have updated my drivers, reinstalled Flash and everything else I can think of, but it remains slow. I had this problem before and it just started working normally from one day to another. Could it be a hardware problem?

  Read the article

• Brand new Seagate HDD has high raw read error rate

  - by kpax

  I've just purchased a brand new Seagate ST31000524AS 1TB HDD. Manufacture date shows as January 2012 (yes that's as new as new can get), so must be one of the new batches from the post-flood Thailand. Anyway, I downloaded a copy of Active Hard Disk Monitor tool to check the S.M.A.R.T. parameters and I find the parameter Raw Read Error Rate is very low. Should I be worried? Will this rectify over time? This hdd is just 7 hours old; what gives? Edit: I meant high raw read error rate - Title updated accordingly

  Read the article

• Multiple servers vs 1 big server performace

  - by pistacchio

  Hi to all! My team of developers has suggested a server structure for an upcoming project we are developing. Our structure is "logical", meaning that the various logical components of the application (it is a distributed one) relies on different servers. Some components are more critical than others and will be subjected to more load. Our proposal was to have 1 server per component but the hardware guys suggested to replace the various machines with a single, bigger one with virtual servers. They're gonna use Blade Servers. Now, I'm not an expert at all, but my question to the guys was: so if we need, for example, 3 2GHz CPU / 2GB RAM machines and you give me 1 machine with 3 2GHz CPUs and 6 GB of RAM it is the same? They told me it is. Is this accurate? What are the advantages or disadvantages of both the solutions? What are the generally accepted best practices? Could you point out some URL reference dealing with the problem? Thank you in advance! EDIT: Some more info. The (internet / intranet) application is already layered. We have some servers on the DMZ that will expose pages to the internet and the databases are on their own machines. What we want to split (and they want to join) are some webservers that mainly expose webservices. One is a DAL that communicates with the database layer, one is our Single Sign On / User Profile application that gets called once per page and one is a clone of what seen on the Internet to be used on our lan.

  Read the article

• MySQL maintenance - how to clear the buffer?

  - by Dougal

  We have a server running our web app (PHP / MySQL) which is SLOW. My predecessor says that: "We use to do database maintenance, which use to clear the buffer, cached and unwanted variables." And I wonder what on earth he means with that statement? Does he mean a simple optimize of the tables? Or the query cache? I understand MySQL but don't really know what he is describing. I would appreciate any pointers. Thanks.

  Read the article

• Is there a way to have a working search bar in Explorer with Windows Search Service disabled?

  - by Desmond Hume

  I had to disable Windows Search Service (turn it off in Windows Features) for the reason that it was constantly using the hard drive in an excessive way (maybe because I've got very large quantities of files on my PC), noticeably slowing down my computer, and the Windows.edb database file grew way too large, about 2.5 GB in size. But the side-effect of it is that now the search bar is gone from any Explorer window and I miss this useful feature. So my question is, is there a way to stop Windows Search Service torturing my hard drive and still being able to search for files and folders directly from Explorer, perhaps using some third-party software?

  Read the article

• What's throttling the database?

  - by Troels Arvin

  Hardware: Intel x86_64 with 192GB of RAM. OS: CentOS 5.4 x86_64. DBMS: DB2 v. 9.7.1 64 bit. During certain special workloads (e.g. parallel REORGs/RUNSTATs), I've seen the server transporting 450MB/s with 25000IO/s (yes, there is probably some storage system caching happening here) while all CPU cores were happily working in an even mix of usermode/wait. And disk benchmark tools can also bring some very satisfying bandwith and IO/s numbers to the table. On the other hand, we also have another scenario: A single rather complex query with at least one large table scan. db2's "list applications" reports that the query is Executing (not locked). IO: At most 10MB/s, 500 IO/s; CPU: two cores in 99.9% wait state, all other cores 100% idle. The tables which the query reads from have been altered to have LOCKSIZE=TABLE, so I would think that lock list work is zero. What's going on in such a situation? What tools/snapshots/... can I use to gain better insight in such a case?

  Read the article

• Chipset GPU causes a massive slowdown

  - by zyboxenterprises

  My AMD Radeon HD 7700 recently broke (fan stopped working and GPU overheated), and now I'm running on internal chipset graphics, and it causes a massive slowdown of the whole PC. I've changed the graphics memory from 32MB (minimum) to 256MB (highest), and it hasn't made any difference whatsoever. I'm using Windows Aero, and disabling it should have made a small difference, but it didn't; the whole PC is still slow. I know that it's not the computer build, because I built it myself, and it was a lot faster when it had the AMD Radeon HD 7700 in it, which is the reason why I believe it's the internal chipset graphics that are causing the problem. Is this behavior normal? I don't have the cash right now to go out and buy a new dedicated GPU. I'm using an ASRock N68C-GS FX motherboard with an AMD FX 4100 (overclocked to 4.3GHZ), with 4GB RAM. The overclock was an attempt to resolve this issue, and it isn't related to this issue that the integrated graphics is causing a slowdown.

  Read the article

• Using wildcard domains to serve images without http blocking

  - by iopener

  I read that browsers sometimes block waiting for multiple images from the same host, and I'm trying to do everything I can to speed up page load times. One caveat: I need to serve files over HTTPS. Any opinions about whether this is feasible: Setup a wildcard cert for *.domain.com. Whenever I need an image, generate an number based on a hash mod 5 of the filename, and append it to an 'img' subdomain (eg img1.domain.com, img4.domain.com, img3.domain.com, etc.); the hash will make any filename always use the same subdomain, and therefore the browser should be able to cache the images Configure a dynamic virtualhost record to point all img#. subdomains to /var/www/img I am looking for feedback about this plan. My concerns are: Will I get warnings when my page has https:// links to multiple subdomains? Is the dynamic virtualhost record I'm talking about even possible? Considering the amount of processing this would require, is it likely to even produce any kind of overall benefit? I'm probably averaging a half-dozen images per page, with only half being changed on each page refresh. Thanks in advance for you feedback.

  Read the article

• Why Can't I Pre-Zip Server Files?

  - by ThinkBohemian

  It's just good common sense to have your server gzip your files before they send them to users (I use Nginx) Is there anyway to save the server some overhead and pre-zip those files for the server, and if not why? For instance rather than giving the server an myscript.js and having the server zip the file and send it to the user, is there a way to create myscript.js.zip so the server doesn't have to?

  Read the article

• linux: accessing thousands of files in hash of directories

  - by 130490868091234

  I would like to know what is the most efficient way of concurrently accessing thousands of files of a similar size in a modern Linux cluster of computers. I am carrying an indexing operation in each of these files, so the 4 index files, about 5-10x smaller than the data file, are produced next to the file to index. Right now I am using a hierarchy of directories from ./00/00/00 to ./99/99/99 and I place 1 file at the end of each directory, like ./00/00/00/file000000.ext to ./00/00/00/file999999.ext. It seems to work better than having thousands of files in the same directory but I would like to know if there is a better way of laying out the files to improve access.

  Read the article

• Laptop is super slow on network

  - by Gary

  So on our network we have a bunch of wireless macs and window Operating laptops, we have a network setup with 802.11g,b,n. All the laptops seem fine except one which is only getting speeds of 54Mb. I have changed the encryption from AES to TKIP and reset the connection, i have updated the drivers, tried plugging it into the LAN and still same slow speed. Apparently the laptop with the slow speed is fine on other networks. I don't know what to do, can anyone help me?

  Read the article

• Jumbo Frames, ISCSI and ESXi

  - by vlannoob

  I have enabled Jumbo Frames (9000) in ESXi for all my vmNICs, vmKernels, vSwitches, iSCSI Bindings etc - basically anywhere in ESXi where it has an MTU settings I have put 9000 in it. The ports on the switches (Dell PowerConnects) are all set for Jumbo Frames. I have a Dell MD3200i with 2 controllers, each with 4 ports for iSCSI. Each of these ports is set to Jumbo Frames (9000) as well. So now the questions: Do I need to log into each Windows Server VM I am running and delve into the NIC properties and manually set it to Jumbo Frames in the NIC properties in the device Manager as well? Whats the best way of testing that Jumbo Frames are indeed working as intended?

  Read the article

• What is the effect on LVM snapshot size when a file block is rewritten with it's original contents?

  - by NevilleDNZ

  I'm exploring using LVM snapshot's to off site incremental archives from a snapshot "master" file system. In essence: simply copy across only the files on the "master" that have changed since the last incremental copy to the "archive". Then snapshot the "archive" to retain the incremental. I am a bit puzzled as to the block usage behaviour of the archive's own incremental snapshot. I'm expecting that LVM is not smart enough to know that the "file block" is actually unchanged, and the a new copy will be allocated and written for the fresh "archive" file system. Can anyone confirm this, or point me to a document/page that gives some hints? BTW: the OS hard disk cache, hard disk physical cache and hard disk itself also doesn't need to do any actual "disk writes" as the "disk block" likewise is unnecessary. Any pointers to discussion of this style of optimisation would also be ineresting.

  Read the article

• Linux Read-Ahead Downsides

  - by JPerkSter

  Hi Everyone, Hope all is well. I have a question regarding read-ahead caching. Are there any downsides to raising the size of the read-ahead cache? On our farm, we're currently running at 256, and upon raising that higher, we are seeing significant throughput gains.   [root@server~]# hdparm -tT /dev/sda /dev/sda: Timing cached reads: 7352 MB in 2.00 seconds = 3677.62 MB/sec 3 Timing buffered disk reads: 244 MB in 3.10 seconds = 78.68 MB/sec [root@server ~]# blockdev --setra 10240 /dev/sda [root@server ~]# hdparm -tT /dev/sda /dev/sda: Timing cached reads: 11452 MB in 2.00 seconds = 5728.52 MB/sec Timing buffered disk reads: 422 MB in 3.17 seconds = 133.04 MB/sec We are running on 2.6. Thanks!

  Read the article

• Why such a dramatic difference in wireless router max. simultaneous connections?

  - by Jez

  Recently, I've needed to look into buying a wireless router for a mission-critical system at work that will need to support quite a few simultaneous connections (potentially a few hundred laptops). One thing I've noticed is that there seems to be a dramatic difference between the max. simultaneous connections different routers can support; see this page for example - anything from 32 to 35,000! Why is there this degree of difference? You'd have thought that if we know how to make routers that can handle thousands of connections, we wouldn't be making stuff that's limited to a pathetic 32 anymore. Is it a firmware thing? A hardware thing? Are low-end manufacturers purposely putting low arbitrary connection limits in so people can be "encouraged" to pay more for high-end routers?

  Read the article

• Optimal disk partitions for database setup (15 Drives)

  - by Jason

  We are setting up a new database system and have 15 drives to play with (+2 on-board for the OS). With a total of 15 drives would it be better to setup all 14 as one RAID-10 block (+1 hot spare) OR split into two RAID-10 sets one for Data (8 disks) and one for logs/backups (6 disks). My question boils down to the following: is there a specific point where having more drives in a RAID-10 setup will out preform having the drives broken into smaller RAID-10 sets.

  Read the article

• Intel Core 2 Duo E6600 versus AMD Athlon II X2 3GHZ

  - by Billy ONeal

  Hello :) I have an Intel Core 2 Duo E6600 (2.4GHZ) in my current desktop, and I have a newer machine with an AMD Athlon II X2 3.0GHZ. I'm wondering how the systems will perform in comparison to one another. I'd like to use the AMD because it's 45nm and uses less power, but I don't want to do so at a loss in perforamnce. Which should perform better? Billy3

  Read the article

< Previous Page | 148 149 150 151 152 153 154 155 156 157 158 159  | Next Page >