HP XP Racks - Manual (Page 169)

Storage System
• Start up the storage system before you start up the hosts, so that AIX
can detect the storage system.
• To delete an LU from the storage system, you must delete the hdisk first,
and then you can delete the LU.
• If you change the storage system's owner controller for the LU, you must
re-configure the hdisk or restart the server.
Notes on Shutting Down a Host
When a cluster environment is not being used and you shut down a host
without inactivating a volume group that satisfies all of the following
conditions, other hosts will no longer be able to operate the volume group:
• The volume group was created by an LU shared by multiple hosts
• The reservation policy for the LU used to configure the volume group was
set to PR_exclusive
Before shutting down a host, execute the following command to inactivate
the volume group:
# varyoffvg volume-group-name
If you shut down the volume group without inactivating it, restart the host,
activate and then inactivate the volume group.
Notes on Errors in a Host
If a cluster environment is not being used and an error occurs on a host
where the reservation policy is set to PR_exclusive in order to exclusively
use an LU, other hosts are no longer able to access the LU. In such a case,
execute the dlmpr utility to clear the HDLM persistent reservation.
For details about the dlmpr utility, see dlmpr Utility for Clearing HDLM
Persistent Reservation on page 7-22 .
While you are performing direct access operations by specifying the hdisk
recognized as an HDLM management-target device, I/O might fail if you
perform the operation below. Before performing this operation, you should
make sure that the volume group is inactive, then perform the direct access
operation by specifying the hdisk recognized as an HDLM management-target
device that is not being used.
¢
Using the dlmpr utility to clear the reserve key.
HDLM Operation
4-3
Hitachi Dynamic Link Manager User Guide for AIX®