Tagged Questions

The tag has no wiki summary.

learn more… | top users | synonyms

7
votes
1answer
134 views

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 ...
7
votes
3answers
465 views

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 ...
7
votes
1answer
93 views

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 ...
3
votes
2answers
266 views

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 <big folder> ionice -c 3 du ...
2
votes
3answers
326 views

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 ...
5
votes
1answer
592 views

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 ...
1
vote
1answer
88 views

Guideline for `nice` priority number?

I'd like a more systematic way for prioritizing my tasks with nice(1). Obviously 0 is "normal", 19 is "lowest priority" and -19 is "highest priority", but what about all the other numbers? If I have ...
5
votes
2answers
1k views

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 ...
2
votes
1answer
419 views

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 ...
5
votes
1answer
869 views

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 ...
3
votes
1answer
316 views

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" ...
2
votes
2answers
299 views

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 ...
1
vote
1answer
223 views

Ionice And Apache2

I am trying to run apache2 at real time priority for this I want to use IONICE but have not been successful. Debian 6 (2.6.32-5-amd64) I use this command ionice -c1 -n0 apache2 But I get this ...
7
votes
2answers
551 views

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 ...
2
votes
1answer
222 views

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 ...
1
vote
1answer
260 views

high load and OOM-killer on domUs while pvmove

Situation xen 4.0.1 dom0 (debian squeeze) domUs all with LVs as disks: disk = [ 'phy:/dev/vg-00/domu-swap,xvda1,w', 'phy:/dev/vg-00/domu-disk,xvda2,w' ]) one VG (vg-00) with 2 PVs Goal Move all ...
2
votes
2answers
452 views

ionice process group?

Is there an easy way to change the I/O priority of a whole group of processes the way renice -g does? It seems like only changing the I/O priority of a single process is supported by ionice. If this ...
6
votes
2answers
1k views

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 ...
5
votes
2answers
522 views

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 ...
1
vote
2answers
884 views

Running a process with both low cpu and I/O priority on rhel4

I've know about running a process under higher & lower priorities for some time, but with different I/O priorities, well that is news to me. My googles have returned information on tools like ...