Monitoring RAID status?

I actually opened a case with f5 to add raid status to the SNMP MIB and they send me information that it's already in there:

config  snmpwalk -v 2c -c public 127.0.0.1 sysPhysicalDiskTable
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskSerialNumber."WD-WCAT1E407050" = STRING: WD-WCAT1E407050
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskSerialNumber."WD-WCAT1E408695" = STRING: WD-WCAT1E408695
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskSerialNumber."B92341DDYGKJ0908HV00" = STRING: B92341DDYGKJ0908HV00
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskSlotId."WD-WCAT1E407050" = INTEGER: 0
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskSlotId."WD-WCAT1E408695" = INTEGER: 0
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskSlotId."B92341DDYGKJ0908HV00" = INTEGER: 0
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskName."WD-WCAT1E407050" = STRING: HD1
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskName."WD-WCAT1E408695" = STRING:
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskName."B92341DDYGKJ0908HV00" = STRING: CF1
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskIsArrayMember."WD-WCAT1E407050" = INTEGER: true(1)
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskIsArrayMember."WD-WCAT1E408695" = INTEGER: true(1)
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskIsArrayMember."B92341DDYGKJ0908HV00" = INTEGER: false(0)
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskArrayStatus."WD-WCAT1E407050" = INTEGER: ok(1)
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskArrayStatus."WD-WCAT1E408695" = INTEGER: missing(3)
F5-BIGIP-SYSTEM-MIB::sysPhysicalDiskArrayStatus."B92341DDYGKJ0908HV00" = INTEGER: undefined(0)

The indexing with the disks' serial numbers is somewhat strange, you'll have to adapt your checks after replacing a drive.