Ubuntu
linux package

  1. Bug #500069
  2. Comment #545

Comment 545 for bug 500069

Revision history for this message
In , perlover (perlover-linux-kernel-bugs) wrote :

I think that i coped with a this bug !
I made some options of kernel and my server works stability and there are no frozen timeouts with high iowait already 10-12 hours!

Detailed info:
My kernel now is 2.6.22.14-72.fc6
Fedora Core 6

This the suggestion is not bug resolving (i think there is bug in kernel and it stays) but this is a workaround. I have read many topics and forums and stopped at these commands:

# echo 50 > /proc/sys/vm/vfs_cache_pressure
# echo deadline > /sys/block/DEVICE/queue/scheduler
# # echo 1 > /sys/block/DEVICE/device/queue_depth
# echo 1024 > /sys/block/DEVICE/queue/nr_requests

The DEVICE is 'hda' or 'sda' for some HDDs. I didn't test queue_depth because for my HDDs (SAS SCSI + RAID10) this file is readonly (no there NCQ supporting as i think). But may be this command will help to you. I don't know.

I suggest anybody who have a frozen timeouts with high iowait to try this turning

I am very glad! Please to try this workaround. I didn't test 'dd' command but my heavy a HDD working has been freezing the server. Now i don't see this.