I'd like to report a suspected hardware issue with the Intel 631xESB/632xESB SATA RAID (aka ESB2) I/O controller.
I have spent the last few weeks trying to track down an issue we have with one of our applications.
The basic problem is that every now and then small writes (22kB) to the disk are delayed by a number of seconds (up to 15 seconds).
It can be reproduced simply with IOMeter.
More detail can be found here:
Having tested the described IOMeter test on 12 different machines using a variety of hardware I have narrowed it down to this specific chipset (3 different machines with the same chipset exhibit this behaviour using RAID1 and RAID10).
I have also managed to rule out the driver as I have a machine with a different chipset (that doesn't exhibit the behaviour) that uses the same Intel Matrix Storage driver version.
I have tried Intel Matrix versions 7.8 and 8.8 and they both exhibit the same problem on the affected machines.
Can Intel confirm this is a hardware issue?
Has anyone else seen this?
Can anything be done about it other than buy new RAID controller cards for the affected machines?