HP A3550A User Guide - Page 109

Disk Array Configurations Configuration type Basic One host One SCSI-2 adapter One SCSI-2 bus One SP Two-SP One host One SCSI-2 adapter One SCSI-2 bus Two SPs Features Applications can continue to run after the failure of a single disk module within a physical disk unit (LUN). Applications cannot continue to run if an SP, SCSI-2 adapter or external SCSI-2 bus fails. Provides the same features as the basic configuration, but with better performance and higher availability. Applications continue to run after the failure of a single disk module. HP-UX 9.04 If one SP fails, the System Administrator must reassign ownership of the failed SP's LUNs to the operational SP by using Grid Manager. Also, the path to the operational SP must be used and can be changed by way of LVM. Once these changes have been made, access to all LUNs on the array is possible. If the SCSI-2 adapter or external SCSI-2 bus fails, no I/O operations are possible between the host and the array. HP-UX 10.x If one SP fails, ownership of the failed SP's LUNs can transfer automatically to the remaining operational SP. If a primary and an alternate path have been configured in LVM, LVM can switch automatically to the alternate path. These operations are transparent to the user. If the SCSI-2 adapter or external SCSI-2 bus fails, no I/O operations are possible between the host and the array. 4-2