We have started to have a few volume dismounts on our NetWare 6.5 SP6 servers in the last few month, using iscsi volumes on a SAN (Equallogic)

5-20-2008 3:18:49 pm: COMN-3.25-1092
Severity = 4 Locus = 3 Class = 0
NSS-3.00-5001: Pool FS2/VOL1 is being deactivated.
An I/O error (22(zlssMSAP.c[1796])) at block 0(file block 0)(ZID 0) has compromised pool integrity.

Console.log also shows

May 20, 2008 3:18:49pm NSS<ZLSS>-3.25-xxxx: zlssMSAP.c[524]
MSAP: Pool "vol1" read error 22

Deactivating pool "VOL1"
Deactivating volume "VOL1"

The volume dismounts, you then have to reactivate the pool via 'nss /poolactivate=vol1' then load the volume again.

We have not run an pool rebuilds or anything like that due to fears of blowing up the volumes. One volume is 1TB in size so is quite large.

Any suggestions on how to further diagnose the source of these disconnects?