HP DL380 G7 Losing Drive Array

Question

I have an HP Proliant DG380 G7 dropping one of it's arrays every hour, on the hour, for 2-5 minutes.

The OS is SBS 2011 Standard, the servers runs Exchange, DC, files & Trend WFBS 8.

I can watch the D Drive disappear for the duration of the problem - then it just comes back up and all is well again. There is no loss of network connectivity, although the mapped drives also disappear.

We thought it might be to do with Sharepoint / VSS writers failing but it looks as though this is a symptom rather than cause. It survives a reboot.

Any ideas as to what could be running on a regular schedule like this?

What does "dropping" mean? Do you have anything in the ILO or HP IML logs? Are the HP agents installed? — ewwhite, Aug 19 '14 at 15:42
Apologies - 'Dropping' just means inaccessible. Diagnostics in the ACU doesn't show anything awry. IML doesn't have any log entries. — jidl, Aug 19 '14 at 15:50
There's a 256mb cache but it's set 100% read, no battery. Only one array of the two drops out, RAID5. — jidl, Aug 19 '14 at 16:21
3 x 300gb on that array. Giving me 558.7 (currently 119 free). — jidl, Aug 19 '14 at 16:49

score 0 · Answer 1 · edited Apr 13 '17 at 12:13

Battery and flash-backed write caches (BBWC/FBWC) are very important when working with HP Smart Array controllers. Performance tends to suffer without them. I suspect you may have a few things happening here...

RAID5 is typically a no-no. Without any write cache, you're susceptible to I/O wait and disk rotational latencies during writes. Whatever is happening hourly is triggered by your software/OS, as there are no scheduled RAID controller tasks that you'd be able to see. If the RAID5 array is unhealthy or experiencing a failing (but not failed) disk, that's even more trouble.

You can temporarily disable the controller write cache barriers to see if that's the issue. In the ACU, you can set the write cache to work even if the BBWC or FBWC is missing. It's dangerous but you can run it long enough to see if the drop-outs persist.

HP DL380 G7 Losing Drive Array

1 Answers1