Questions tagged [ionice]
25 questions
15
votes
2 answers
rsync ionice destination
To avoid rsync to starve the system and network we use ionice when starting rsync and set the --bwlimit parameter. For example:
ionice -c2 -n7 rsync -aH --bwlimit=30000 /foo root@dest.com:/
This does indeed help to ensure the source server remains…
Jason Smith
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9
votes
1 answer
Use cases for having different process priority for CPU and IO?
Linux processes can have different CPU and IO priority (nice and ionice).
Why is there a need to have different CPU and IO priority?
Is there any real world usage for having them different?
What real world use cases have you found that need…
Eduardo
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8
votes
1 answer
rrdgraph generation fails on high IO load
We have a 4 core CPU production system which does a lot of cronjobs , having constant proc queue and an usual load of ~1.5.
During night time we do some IO intensive stuff with postgres.
We generate a graph showing the load/memory usage…
Dennis Nolte
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8
votes
3 answers
How to keep subtree removal (`rm -rf`) from starving other processes for Disk I/O?
We have a very large (multi-GB) Nginx cache directory for a busy site, which we occasionally need to clear all at once. I've solved this in the past by moving the cache folder to a new path, making a new cache folder at the old path, and then rm…
David Eyk
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7
votes
2 answers
nice, ionice are not enough
I have a script that starts big, CPU and memory consuming tree of processes. There is Python and executables down there, but everything starts with single bash script and python subprocesses.
During the execution, rest of system is completely…
MateuszL
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7
votes
1 answer
Making the kernel aware of device colocation
I have a server with a big hardware RAID6 array that's been configured with two volumes, presented by Linux as sda and sdb (yeah, I know, but it's a rented colo that came configured this way, and sadly I have to live with it).
I have an…
Flup
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7
votes
2 answers
Can I throttle tar without ionice?
My tar command
tar --remove-files -cvif 2011-08-02_14-05-09.tar 2011-08-02_14-05-09
Writes 80MB/s. That's beyond the capacity we can spare because MySQL starts queuing up writes and eventually we get monitoring alerts cause systems won't wait…
kvz
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7
votes
2 answers
How to set i/o priority for nfs client processes?
The configuration is: A linux server and a nas box (netgear) acting as nfs server.
It is easy for a single process on the linux server to use all i/o bandwidth by simply copying a file from the nfs share to the nfs share. The i/o channel is jammed…
Moritz Both
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6
votes
1 answer
How long is the "defined grace period" for the idle scheduling class of the CFQ io scheduler?
The ionice man page says
A program running with idle io priority will only get disk time
when no other program has asked for disk io for a defined grace period.
Where is this "grace period" defined? Is it visable/tunable (perhaps via /sys)?
jhfrontz
- 273
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5
votes
1 answer
ionice vs. Software-RAID
Does ionice work in Software-RAID environments?
I cannot set the CFQ scheduler for the md devices, because there is no file /sys/block/md0/queue/scheduler .
It seems that the scheduler settings for the underlying disks are not propagated to the raid…
der_flo
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- 3
5
votes
2 answers
ionice idle is ignored
I have been testing the ionice command for a while and the idle (3) mode seems to be ignored in most cases.
My test is to run both command at the same time:
du
ionice -c 3 du
If I check both process in iotop I see…
Ferran Basora
- 151
- 3
5
votes
1 answer
How do I test the effect of ionice (against a device using the cfq scheduler)?
I'm trying to construct an experiment to measure the effect of ionice. What I'd like to do is to (per another answer on serverfault) cause frequent enough I/O that a sufficiently "niced" process is starved of any I/O.
Based on another answer on…
jhfrontz
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3
votes
3 answers
Is it possible to assign a nice and ionice priority to all scripts executed by cron daemon?
To be a bit more concrete:
I have a Debian Squeeze Linux machine with a web application that should become available all over the planet. Until now I had a bunch of resource consuming cronjobs each night (in Europe) without much impact on regional…
Miguel ZP
- 31
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3
votes
2 answers
ionice without effect
System is Ubuntu 10 LTS 64bit (2.6.35.31), I'm running on xen 4.0, no services active, cron stopped, scheduler is cfq for the disk /usr is mounted from:
time find /usr -exec stat {} \; > /dev/null 2>&1 &
giving
real 0m35.760s
user 0m0.270s
sys…
tim
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2
votes
0 answers
rsync: Maximum nice to keep system responsive
Unfortunately a background rsync reduces the responsiveness of a server.
I search a way to have maximum niceness for this background task, to keep the server respond fast.
My current wrapper commands are this:
nice -n19 ionice -c3 nocache
Source:…
guettli
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