Virtual Machines

I/OTest script to check if the disk I/O is causing slow performance

Slow VM Performacne, use IOTest to see if the disk IO is the culprit

This script will test the disk IO by copying 500Mb of data using the same block size as eDir uses and with the same api eDir uses “fdatasync”.
This writes 500 Mb of data each iteration to the iotest.log in the dib directory, usually the /var/opt/novell/eDirectory/data/dib/
It will overwrite the previous data in the iotest.log each time it runs.  Anything under 100 MB/s is a concern and will cause slowness for eDirectory and possible memory build up.  IO causes a bottleneck for events to be written to disk.  A build up of memory by ndsd can cause a ndsd to take all available memory (both virtual and resident) causing ndsd to core.

If slow IO writes are seen with the iotest script begin the process of adding hard drives and reducing the… Continue reading