5
votes
0answers
47 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 ...
6
votes
3answers
368 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
89 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 ...
2
votes
3answers
248 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
560 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 ...
5
votes
1answer
794 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
289 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
428 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 ...
5
votes
2answers
500 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
863 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 ...