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Questions tagged [io]

IO (or I/O) is an abbreviation for input/output, most commonly referring to disk input/output.

IO (or I/O) is an abbreviation for input/output, most commonly referring to disk input/output.

401 questions
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Analysing Disk IO Traffic

I am running a web server (Ubuntu 11.04) that exhibits unexpected high write traffic. When the server is not supposed to write at all, the amount of write traffic is comparable to the read traffic. Concerned about unnecessary write operation, I…
linqu
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Fastest security check of file tree on NFS

I am currently experiencing very bad performance using the following on an NFS network folder: time find . | while read f; do test -L "$f" && f=$(readlink -m $f); grp="$(stat -c %G $f)"; perm="$(stat -c %A $f)"; done Question 1) Within the loop…
fungs
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Using ionice Over Cluster

Background: I use a computing cluster at work (4 slave nodes and 1 head node) that uses the SGE job scheduler. Recently we've been running jobs that do some heavy IO and it has been slowing down shell/vim usage (small IO, but we need it running…
sequenceGeek
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Nginx+apache2 ubuntu server crashed with several hundreds of visitors

I have Linode 768mb RAM server on Linode. And i have Wordpress blog. On my server installed ubuntu, nginx as frontend and apache2 as backend. And i have APC and memcache modules. Sometimes site is crashing. But CPU usage of server is less than the…
Bohdan Hdal
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I/O and CPU differences between dedicated hosting and Amazon EC2

I'm looking to run a high population Minecraft server (150+ players online at a time). For those unfamiliar with the Minecraft server, it is a (non-multithreaded) application written in Java (some plugins rely on multithreaded products such as…
Tony
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How can I determine the specific file referenced by fs_usage, which is listed by block

I was investigating a problem on a Mac OS X 10.6.8 Server, where users were complaining of access slowdowns. Network throughput slowed to a crawl. It felt like the server was overburdened. System metrics showed the data rate at the NIC to be under…
flumignan
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2 answers

Detecting Disk Writes Linux

my webserver running centos 5.7 is showing quite a lot of disk write activity which I cannot explain really. I run a few websites on this server with the help of nginx and php-fpm and xcache. On the file-system i have added noatime. Now this is…
Mr.Boon
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How to track cause of blocking IO problems

I move between multiple subnets and networks on a regular basis. I'm often faced with Explorer and other programs that stall in what appears to be an IO request. I'm trying to find a consistent way to track which request is stalling. Tools like…
user8553
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3 answers

IOs reads writes per file

My target is to equally separate mysql database across the number of drives, using symbolic links on tables. Now I can not seem to find the way to check IOs, reads, writes per table on mysql. So now I am thinking maybe there is some way in linux to…
Katafalkas
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High disk I/O activity in CentOS server

I have about 16 websites in a CentOS dedicated, and I am having some problems on high traffic hours, it seems to be a high disk I/O activity causing a general slowdown. I've installed atop and this is what I see on the bottom (the server has been…
triiim
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inonice not working properly in xen dom0

I have a Xen Dom0 (3.2) with a bunch of domUs (paravirt). DomU VBDs are on local LVM volumes. Now I want to get backups of the LVM volumes using snapshots. I use rsync ioniced to idle (ionice -c3). I have verified that the rsync processes are really…
tim
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IO and bus errors on Ubuntu Server

I've got an old computer running Ubuntu Server 10.04, which acts as router, file server and web server. A couple of weeks ago I inserted a PCIe video card, since the motherboard did not have any video outputs. Since then, I now occasionally get IO…
nip3o
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Expected throughput when re-building RAID array?

I'm just doing some testing on a NAS RAID array we've been lent to see if we want to deploy it. Just to see whats what, I decided to see what kind of network performance we get when it's re-building a RAID-5 array. I'm noticing that network…
Mark Henderson
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How to reduce mysql disk io?

mysql> explain SELECT * -> FROM (`items`) -> WHERE `states` = 'A' -> ORDER BY `updated_date` desc -> LIMIT 20520,…
joetsuihk
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comparing disk performance of machines

I am in the process of moving applications running on old Linux machines onto VMs. As part of this, I need to justify the VMs have at least the capacity (i.e. CPU speed, RAM, disk, disk speed, network speed...), otherwise the moves will slow the…
Carey
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