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Questions tagged [iowait]

8 questions
9
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1 answer

top says IOWAIT is high, how to I find the culprit processes

I know I should not do it but I run some Ubuntu system from an USB flash drive, in persistent mode, and it is painfully slow. "top" tells me it is not because of CPU, it is because of IO, ie high %wa. I have already remove the swap, but to optimize…
JeanHuguesRobert
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If "top" indicates CPU is spending 10% on %wa (iowait), does that mean the CPU is idle?

I am referring to the Linux top command. If it indicates 10.4% was spent on wa, does that mean 10.4% CPU was available for other processes? top - 09:40:45 up 178 days, 34 min, 1 user, load average: 0.32, 0.43, 0.42 Tasks: 173 total, 1 running,…
Sabya
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Disk size varies - MooseFs

I have 4 moosefs chunkservers with 8 2.7 TB storage on each, I mount them using mfsmount and then export with nfs. Recently I noticed high iowait on my chunkservers, then huge mount size drops, see the graphs.
Edik Mkoyan
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Cloned partion to new drive - IO Wait crushes server

I am running Ubuntu 9.10 and recently needed to upgrade the HD. I bought a 3TB 7200 64mb cache replacement drive. Created two partitions one at around 2gb the other for the remainder. The machine is running 64bit and has 24gb of ram in it. Using…
Ominus
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Slow OSX - how to determine the bottleneck

I am using OSX 10.7.5 and my OSX is becoming a bit unresponsive, comparing to what it was like before. Sometimes just opening new window of browser or terminal takes few seconds or the Dock hovering effect is not fluent. At these moments I watch…
Vojtěch
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How to fix very high w_await on linux desktop?

My Linux (Debian sid) desktop started to become sluggish in the last few weeks. When I investigated, I found that: There is no ram shortage -- the system regularly uses only half of its 4G, there is more than 1G free even when counting caches and…
Shai Berger
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Ubuntu lucid, maverick high iowait

I'm using Ubuntu, and I've got the same problem with Lucid and Maverick. From time to time, especially a few minutes after boot, the iowait goes between 50-100% and the box is unusable. Everything that tries to access the disk freezes. I have the…
netom
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RHEL7 - High CPU load when write to NAS

I do not understand, what is the reason for very high "load average" reported by top. This is RHEL 7. The problem is repeatable. We have one remote NAS and when one user-space process start to write extra large files there (e.g. size of 15 GB) then…
meolic
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