SCSI error on Oracle database disk array

I have an Oracle ASM database on a Dell Powervault 220S disk array.
The other day, the ASM database went down with the following errors:

ORA-27091: unable to queue I/O
ORA-27070: async read/write failed
OSD-04016: Error queuing an asynchronous I/O request.
O/S-Error: (OS 1117) The request could not be performed because of an
I/O device error.


The Windows Event Viewer showed an error at this same time that said
"The device \Device\Scsi\mraid35x1 did not respond within the timeout
period". This was an Event ID of 9.

Doc on this said to check connections, cables, etc. I stopped, re-
seated, rebooted, etc. I checked the drivers, they are up to date
(although they're about 5 years old). The disks show no errors, but
the +DATA diskgroup cannot be mounted in ASM. When I try to manually
mount the disk group I get the "ORA-15096 signalled during mount of
diskgroup DATA" error.


Any ideas of what I can do here? Am I hosed? If it's not the disk,
is it the Perc controller?