Search Results

Search found 20904 results on 837 pages for 'disk performance'.

Page 146/837 | < Previous Page | 142 143 144 145 146 147 148 149 150 151 152 153  | Next Page >

• A space-efficient guest filesystem for grow-as-needed virtual disks ?

  - by Steve Schnepp

  A common practice is to use non-preallocated virtual disks. Since they only grow as needed, it makes them perfect for fast backup, overallocation and creation speed. Since file systems are usually based on physical disks they have the tendency to use the whole area available1 in order to increase the speed2 or reliability3. I'm searching a filesystem that does the exact opposite : try to touch the minimum blocks need by an aggressive block reuse. I would happily trade some performance for space usage. There is already a similar question, but it is rather general. I have very specific goal : space-efficiency. 1. Like page caching uses all the free physical memory 2. Canonical example : online defragmentation 3. Canonical example : snapshotting

  Read the article

• Is Software Raid1 Using mdadm with a Local Hard Disk and GNDB Possible?

  - by Travis

  I have multiple webservers which use many small files to created dynamic web pages. Caching the web pages isn't an option. The webserver also performs writes so I need a synchronous filesystem. I'm looking to maximise performance as it's my understanding that small files is the weakness (to varying degreess) of a cluster filesystem over ethernet. Currently I'm using Centos 5.5, 64 bit. Since it's only about 300MB of data, I'm looking at mdadm using RAID-1 with the GNBD and a local hard disk using the "--write-mostly" option so the reads are done using the local hard disk. Is this possible? If so, is there any advantage to making it a tmpfs disk instead of a local hard disk? Or will the files on the local hard disk just get cached in RAM anyway so I won't see a performance gain by using tmpfs, assuming there's enough RAM available?

  Read the article

• Average mail quota usage: tricks to implement unlimited email quota.

  - by Marco Demaio

  I suppose that hosters who provides unlimited mail quota are only claiming it unlimited, and hope that they won't run out of disk space. Correct me if I'm wrong. In order to do such trick they will have probably to calculate the average real quota used by the average user. Let's say on a 100 GB space hosting I offer to 20 x 1GB emails, obviously if all user fill their mail my server would stop working cause they would require 200 GB, but I think I can expect this trick to work cause it will never happen (or it's extermly unprobable) that all user fills up all their mails. But the QUESTTIONS are: What's the average email usage? Can we say that a user normally fills up 1/2 or 1/3 of the quota you provide him? Thanks to any answers/suggetions you might provide.

  Read the article

• How SSD hard drive affected speed of your website (asp.net/linq/ms sql database)

  - by Sergey Osypchuk

  I have a small database (<1G) But we have a lot of complex logi? in website and client complains on render time, which is 3-5 seconds. We are not google, and thousands of users a day is our dream, so size is not a problem, but speed is important. Can anybody share with experience with SSD drives for ASP.NET (MVC)/LINQ/MS SQL based application ? How you performance increased? UPDATE: this whitepaper states that it will be 20 times faster. http://www.texmemsys.com/files/f000174.pdf

  Read the article

• Will Windows Barf on Constant Video Driver Overwrite?

  - by Maarx

  So, I've got a Win7 64-bit gaming PC with GTX 260's. Recently, StarCraft 2 had an issue with flickering, which NVidia fixed with a new set of drivers. However, these new drivers induce unplayable graphical errors with Neverwinter Nights 2, something me and my friends still play from time to time. I am seeking advice on the "best" way to rectify this situation, to be able to switch between two driver releases, without compromising the stability of my system (if Windows stability isn't an oxymoron). I'm wondering if Windows 7 is structured in such a way that I can constantly reinstall these two sets of drivers back and forth overtop each other, possibly six or eight times a day, without very quickly driving myself to reformat to maintain that "just like new" performance. I'm loathe to have to reformat the drive and maintain two copies of the operating system, but I'll do it if I have to.

  Read the article

• Is Page-Loading Time Relevant?

  - by doug

  Take this (ServerFault) page for instance. It has about 20 elements. When the last of these has loaded, the page is deemed "loaded"--but not before. This is certainly the protocol used by our testing service (which is among the small group of well-known vendors that offer that sort of service). Obviously this method is based on a clear, definite endpoint--therefore it's easy to apply w/ concomitant reliability. I think it's also the metric used by the popular Firefox plugin, 'YSlow.' For my employer's website, nearly always the last-to-load items are tracking code, tracking pixels, etc., so from the user's point of view--their perception--the page was "loaded" well before it had actually loaded based on the criterion used by our testing service (15-20% is a rough estimate). I'm sure i'm not the first person to consider this nor the first to wonder if it is causing micro-optimization while ignoring overall system-level, or user-perceived performance. So my question is, are there are other more practical (yet still reasonably precise) measures of page loading time?

  Read the article

• How do I know if my disks are being hit with too many I/O reads or writes or both?

  - by Mark F

  I know a bit about disk I/O and bottlenecks relating to this especially when relating to databases. How do I really know what the max I/O numbers will be for my disks? What metric might be available to me for working out roughly (but needs to be a good approximation) of how much capacity (if you will) have I got left available in I/O. I've seen it before where things are bubbling along nicely and then all of a sudden, everything screams to a halt, and it ends up being an I/O bound problem. Is there a better way to predict when I/O is reaching its limits? This article was interesting but not giving the answer I desire. So, is my best bet surrounding just looking at 'CPU I/O WAIT'? There must be a more reactive method than this.

  Read the article

• Is it normal for a SAS drive to have a few bad blocks, or should I replace my drive ASAP?

  - by Nate

  I have a drive—part of a RAID 1 mirror—that has two bad blocks. Adaptec Storage Manger e-mailed me when it detected the blocks. It shows 4 medium errors for that drive, but state is still “optimal”. This is my first time using Adaptec RAID controllers. I don’t know if an occasional bad block is normal, or if I should immediately replace that drive. Update: The drive failed later the same day! The disk subsystem is: Adaptec 6405 with ZMM (2) Seagate near-line SAS drives (ST31000424SS) The other drive hasn’t reported any bad blocks yet. I am running a consistency check.

  Read the article

• Nagios remote monitoring: NRPE Vs. SSH

  - by sam

  We use Nagios to monitor quite a few (~130) servers. We monitor CPU, Disk, RAM and a few other things on each server. I've always used SSH to run the remote commands, purely because it requires little to no additional config on the remote server, just install nagios-plugins, create the nagios user and add the SSH key, all of which I've automated into a shell script. I've never actually considered the performance implications of using SSH over NRPE. I'm not too bothered about the load hit on the Nagios server (It's probably over-speced for what it does, it's never been over 10% CPU), but we run each remote check every 30 seconds and each server has 5 different checks performed. I assume SSH requires more resources for each check but is there a huge difference? (I.E. enough of a difference to warrant the switch to NRPE). If it's any help, we monitor a mix of physical servers (Normally with 8, 12 or 16 physical cores) and Amazon EC2 medium/large instances.

  Read the article

• Phantom Local Disks appearing in my drive list

  - by Paul

  I seem to have several phantom Local Disks mapped to different letters that are of 0 bytes in size. Strangely, they do not show up when I view my drives through Windows Explorer. But if I open an application such as ACDSee Pro or MS Word and then go to open a file I can see all these Local Disks mapped to different letters. This means when I plug in my external hard disk it ends up mapped to letter R instead of its usual G which messes up any programs I have pointing to it by default. How did they get there and more importantly, how do I get rid of them? I'm on a Window 7 Home Premium 32 bit machine.

  Read the article

• What service can hold CPU at lowest frequency possible when on battery load under Ubuntu?

  - by vava

  When I'm running on battery even with "performance" frequency scaling governor, something regularly lowers CPU speed to it's lowest value. I don't really want that, my AC strip usually in another room so I don't really need to save power. How can I find what service doing that? laptop_mode is disabled so that's not it. Update: Looks like CPU being scaled down only if it is under load. If it is more or less idle, it could stay on any frequency pretty much forever, but once it gets loaded, it quickly jumps to it's lowest frequency. Another update: Something sets maximum frequency CPU can have. Ubuntu launchpad bug 242006

  Read the article

• MySQL Unions/Subselects not utilizing keys from associated tables

  - by Brett

  I've noticed by doing EXPLAINs that when a MySQL union between two tables is used, mysql creates a temporary table, but the temp table does not use keys, so queries are slowed considerably. Here is an example: SELECT * FROM ( SELECT `part_number`, `part_manufacturer_clean`, `part_number_clean`, `part_heci`, `part_manufacturer`, `part_description` FROM `new_products` AS `a` UNION SELECT `part` as `part_number`, `manulower` as `part_manufacturer_clean`, `partdeluxe` as `part_number_clean`, `heci` as `part_heci`, `manu` as `part_manufacturer`, `description` as `part_description` FROM `warehouse` AS `b` ) AS `c` WHERE `part_manufacturer_clean` = 'adc' EXPLAIN yields this: id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY <derived2> ALL (NULL) (NULL) (NULL) (NULL) 17206 Using where 2 DERIVED a ALL (NULL) (NULL) (NULL) (NULL) 17743 3 UNION b ALL (NULL) (NULL) (NULL) (NULL) 5757 (NULL) UNION RESULT <union2,3> ALL (NULL) (NULL) (NULL) (NULL) (NULL) In this case, part_manufacturer_clean and manulower are keys in both tables. When I don't use the subselects and union, and just use one table, everything works fine. I'm not sure if the issue is with the union or with the subselects. Is there any way to union two tables and still use keys/indexes for performance?

  Read the article

• need for tcp fine-tuning on heavily used proxy server

  - by Vijay Gharge

  Hi all, I am using squid like Internet proxy server on RHEL 4 update 6 & 8 with quite heavy load i.e. 8k established connections during peak hour. Without depending much on application provider's expertise I want to achieve maximum o/p from linux. W.r.t. that I have certain questions as following: How to find out if there is scope for further tcp fine-tuning (without exhausting available resources) as the benchmark values given by vendor looks poor! Is there any parameter value that is available from OS / network stack that will show me the results. If at all there is scope, how shall I identify & configure OS tcp stack parameters i.e. using sysctl or any specific parameter Post tuning how shall I clearly measure performance enhancement / degradation ?

  Read the article

• Is it dangerous to add/remove a hard-drive to a Windows machine which is in stand by?

  - by Adal

  Can I add a SATA drive to a Windows 7 machine which is in standby mode? The hardware supports hot-plug. Could pulling the drive out while in standby corrupt the data on the drive (unflushed caches, ...)? Does Windows flush before standing by? How about swapping a drive with another drive of different kind (SSD - mechanical disk) and size, also while in stand-by. Could the OS when waking up believe that the old drive is still there, and write to it and thus corrupt it, since the new one has different partitions and data?

  Read the article

• High Lock Wait ratio in MySQL

  - by FunkyChicken

  on my site I log every pageview (date,ip,referrer,page,etc) in a simple mysql table. This table gets very little selects (3 per minute), but a lot of inserts. (about 100 per second) Today I changed this table from an InnoDB table to a MEMORY table, this made sense to me to prevent unnecessary hard disk IO. I also prune this table once per minute, to make sure it never get's too big. -- Performance wise, things are running fine. But I noticed that while running tuning-primer, that my Current Lock Wait ratio is quite high. Current Lock Wait ratio = 1 : 561 My question: Should I worry about this Lock Wait Ratio? And is there something I can change in my my.cnf to improve things so that the lock wait ratio isn't so high?

  Read the article

• Why does my general frame rate slow down to 40fps randomly?

  - by Joshua

  This has been bugging me for a while. Every once in a while, I find my computer to be sort of laggy and I thought it was because it was busy or something. However, I recently noticed that it wasn't any performance issue...I thought my computer was laggy because the frame rate slowed from 75fps right down to ~40 fps and caused very visible tearing. This is not rare. It happens many, many times a day. I have no idea what is happening...I have an AMD 5670 on Windows 7 32-bit by the way, and I've heard bad things about AMD's driver support. Could this be the problem? P.S. The frame rate slowdown is not just for games (I rarely play games, and have not played games in the time since I noticed this problem), it seems it's an issue for the entirety of Windows. I first noticed the tearing when I was moving around tabs in Google Chrome.

  Read the article

• Per process I/O accounting on AIX

  - by ipozgaj

  Is there a way of getting per process I/O statistics on AIX, i.e. to get current disk I/O rate of a process? Commands like iostat, nmon, topas etc. can't display such data. Filemon also doesn't help. Actually, what I would need is something much like iotop(1) command on Linux. Update: it seems there is no builtin command(s) to do this. I will most probably make my own by using the SPMI API.

  Read the article

• Xen find VBD id for physical disks

  - by Joe

  I'm starting a xen domU using xm create config.cfg. Within the config file are a number of physical block devices (LVs) which are added to the guest and can be accessed fine when it boots. However, at a point in the future I need to be able to hot unplug one of these disks using the xm block-detach command. This command, however, requires the vbd id of the device to be detached and I can't find a way to find the device id for a particular disk 'plugged in' at start up. Any help is much appreciated!

  Read the article

• A space-efficient filesystem for grow-as-needed virtual disks ?

  - by Steve Schnepp

  A common practice is to use non-preallocated virtual disks. Since they only grow as needed, it makes them perfect for fast backup, overallocation and creation speed. Since file systems are usually based on physical disks they have the tendency to use the whole area available1 in order to increase the speed2 or reliability3. I'm searching a filesystem that does the exact opposite : try to touch the minimum blocks need by an aggressive block reuse. I would happily trade some performance for space usage. There is already a similar question, but it is rather general. I have very specific goal : space-efficiency. 1. Like page caching uses all the free physical memory 2. Canonical example : online defragmentation 3. Canonical example : snapshotting

  Read the article

• Would upgrading memory from 4GB to 8GB on my laptop solve swapping issues?

  - by Tom

  I have a laptop with 4GB of memory with Windows 7 on it and I often experience with Eclipse that it is swapped out to disk. On the net they usually write 4GB of RAM is more than enough for average use and aside from Eclipse+Android Emulator I don't really use other extra apps, yet Eclipse is always swapped out if I haven't used it for a while (say, 1 day) and it is annoying it to wait for it to be resurrected from swap. My question is: would an upgrade to 8GB solve the issue of swapped out applications? With 8GB would windows 7 keep everything in memory? Or it wouldn't change anything and Eclipse would be swapped out regardless of the amount of memory, because Win 7 has a habit of kicking out every application from memory which hasn't be used for a while?

  Read the article

• Ways to setup a ZFS pool on a device without possibility to create/manage partitions?

  - by Karl Richter

  I have a NAS where I don't have a possibility to create and manage partitions (maybe I could with some hacks that I don't want to make). What ways to setup multiple ZFS pools with one partition each (for starters - just want to use deduplication) exist? The setup should work with the NAS, i.e. over network (I'd mount the images via NFS or cifs). My ideas and associated issues so far: sparse files mounted over loop device (specifying sparse file directly as ZFS vdev doesn't work, see Can I choose a sparse file as vdev for a zfs pool?): problem that the name/number of the assigned loop device is anything but constant, not sure how increasing the number loop device with kernel parameter affects performance (there has to be a reason to limit it to 8 in the default value, right?)

  Read the article

• Why won't Windows use the other CPU cores?

  - by revloc02

  In Windows Task Manager the Performance tab shows the first CPU maxed out, the other 7 just idling along with the occasional spike. What gives? More info: I've got 8GB and only 4.5GB are being used. The Processes tab has no indication of any process hogging processing power. In fact System Idle Process is 98-99. When I program stuff and have like 8 to 12 applications going (several directly unrelated to programming of course) my computer slows to a crawl. Sysyem Info: Intel Core i7-2600K Processor (quad-core with hyper-threading), 8GB RAM, Intel BOXDZ68BC LGA 1155 Motherboard, 500GB HDD

  Read the article

• writting becomes slow after few writes

  - by user1566277

  I am running an embedded Linux on arm with a SD-Card. While writing huge amounts of data I see bizarre effects. E.g, when I dd a 15 MB file few times, it writes the file (normally) in less than 2 Secs. But After lets say 3-4 times it takes sometimes 15 to 30 Seconds to write the same file. If I sync after writing the file, then this does not happen but sync takes long time too. If there is enough gap between writing two files than presumably kernel syncs itself. How can I optimize the whole performance so that write should always finish inside 2 Seconds. The File system I am using is ext3. Any pointers?

  Read the article

• Postfix smarthost with diffent relayhosts and sender dependant authentication

  - by mattinsalto

  I've setup postfix as smarthost with different relayhosts and sender dependant authentication. Everything works ok, but I have a performance question. Is it better to send all the email corresponding to a domain through only one account? I mean, now I'm sending each message authenticating to the relay host with the sender credentials. Example: If I have 5 email accounts and I send 10 simultaneous messages from each account, How many times is postfix login to the relay host if I have sender dependant authentication? 5 times? once for each sender 50 times? once for each message If I send all the messages corresponding to one realy host through one account, how many times does postfix login to the relay host? only once? Thanks in advance.

  Read the article

• How to clone & restore virtual box hard drive

  - by user23950

  What I want to do is to clone my virtual box hdd with dual boot os. Xp and Vista. I'm using acronis and back it up on a flash drive. And end up with the flash drive that is partitioned. 2 partitions just like the virtual box hard disk. What do I do to restore it. I'm running acronis inside virtual box. What do I do to make use of the backup and actually restore what I've back up. And to be able to boot to xp and vista again inside virtual box. Please help.

  Read the article

< Previous Page | 142 143 144 145 146 147 148 149 150 151 152 153  | Next Page >