HP XP External Storage Software - Manual (Page 44)

• Do not map multiplatform volumes of external arrays as internal LDEVs.
• After executing the Check Paths & Restore Vol., Disconnect Subsystem, or Disconnect Volume
command, click the Refresh button ( ) on the Command View XP or XP Remote Web Console
main pane to update the information, and check the current status.
• When the external LU's status is Blockade, execute the Check Paths & Restore Vol. command.
If the Check Paths & Restore Vol. command does not restore the external LU's status, the path to
the external array might be blocked. In this case, see
Troubleshooting External Storage XP for
instructions on restoring the path to the external array.
If the external LU's status remains Blockade even though you restored the path to the external array
and executed the Check Paths & Restore Vol. command, execute the Restore command.
• If you execute the Disconnect Subsystem or Disconnect Volume command when I/Os from the
open system host are in progress, host I/Os to the specified volume are forcibly stopped. When
executing the Disconnect Subsystem or Disconnect Volume command, stop host I/Os, and unmount
the volume from the host.
• If the volume is online from the mainframe host, you cannot execute the Disconnect Subsystem or
Disconnect Volume command. Stop host I/Os to the volume, and perform the Vary Offline operation.
• You cannot execute the Disconnect Subsystem or Disconnect Volume command for external LUs
that include LDEVs set as copy pairs for Flex Copy XP, Business Copy XP, ShadowImage for z/OS,
Continuous Access XP Journal, Universal Replicator for z/OS, Continuous Access XP, TrueCopy
for z/OS, or Snapshot XP. However, if the copy pair status is PSUE, you can execute these
commands. When the external LU is set as a pool volume (pool-VOL) and that Snapshot XP pair's
status is PAIR, you can execute these commands.
• You cannot execute the Disconnect Subsystem or Disconnect Volume command for external LUs
that include LDEVs for which Auto LUN XP's migration processing is in progress.
• When executing the Disconnect Subsystem or Disconnect Volume command, the displayed
information for Ex-Dev. Status in the Device list becomes Cache Destage. Even if there is no data
left in cache memory, the displayed status stays Cache Destage until the Disconnect Subsystem or
Disconnect Volume command processing is complete.
• When the Disconnect Subsystem or Disconnect Volume command is executed and all data in cache
memory is written to the external LU, the displayed information for Ex-Dev. Status in the Device list
becomes Disconnect.
• When using the mapped external LU from the mainframe OS, set the Missing Interrupt Handler
(MIH) timer to 45 seconds, which is the recommended value.
• In the internal processing, the external LU's RAID level is handled as RAID-1 across the board. A
bar (–) appears on the Command View XP or XP Remote Web Console panes. The external LU's
RAID level is reported as RAID-1 when information about the external array is reported to
higher-level devices (OS).
• Table 4 and Table 5 show the recommended application level for the mapped external LU according
to the external LU's HDD type.
Table 4 When external LU's emulation type is OPEN
HDD type Application
HD-FC S-ATA FC
Not Recommended Not Recommended Database
Online
Transaction
Processing
(OLTP)
Preparing for External Storage XP operations 44