Slow RAID IO on PE2970
J.Ede at birchenallhowden.co.uk
Fri Mar 20 04:14:28 CDT 2009
> We've done some more work on this box moving data off it again so we
> can look at redoing the RAID structure...
> When we've a single IO stream we can easily read 20MB/s off the array
> and iostat still shows the array as not stressed at all. However, when
> its in production (its an openfiler box with ESXi hosts connecting to
> it via NFS for the virtuals) then the IO drops to what we saw earlier
> which is a few 10's or 100's of KB/s and 100% utilisation.
> It all seems a bit odd... Also when copying the data off the drives
> every 5 mins or so the IO data rate suddenly drops to zero briefly. I
> think we'll run a full test on the RAID controller and the disks as the
> IO still seems poor and RAID 5 on those disks should be able to handle
> a better rate than we were seeing.
Further update. We now have the box back in our office for investigation... Using the OM Live CD I've looked in Server Administrator which reports everything ok, but when I run the DELL Online Diags then on one of the drives I'm getting the following reported.
'Device reported Servo Failure'
Could this be the problem all along? A Dud drive?
More information about the Linux-PowerEdge