HP 3PAR Cluster Extension Software Administrator Guide (5697-2047, June 2012)

fail to come online when the host OS does not detect the LU permission change. As a workaround,
configure the HP 3PAR Cluster Extension script multipath_rescan.sh as a PostExecScript to
rescan the disks before they are brought online.
Configuring the rescan script
The multipath rescan script is available in the directory /opt/hpclx3par/sample/
multipath_rescan.sh.
To configure the script to run as a PostExecScript:
1. Copy the multipath_rescan.sh script to the /etc/opt/hpclx3par/conf folder, and
rename the file as follows:
• RHCS: multipath_rescan_ServiceName.sh
• SLE HA: multipath_rescan_ResourceGroupName.sh
• HP SG on Linux: multipath_rescan.sh
2. Open the script file and enter the user-friendly names of all multipath devices that are in the
volume groups configured for the RHCS service, HP Serviceguard package, or SLE HA resource
group.
For instructions on finding the user-friendly name of a multipath device, see “Finding the
user-friendly name of a multipath device” (page 63)
In the following example, you specify the user-friendly names (mpathab, mpathac, and
mpathad) for the variable MULTIPATH_DEVICES:
MULTIPATH_DEVICES=( mpathab mpathac mpathad )
3. Enter the multipath_rescan.sh script for the PostExecScript object in the HP 3PAR Cluster
Extension resource configuration file.
You must specify the full path name of the multipath_rescan.sh script. For example:
Finding the user-friendly name of a multipath device
The multipath_rescan.sh script requires that you enter the user-friendly names of the multipath
devices.
To obtain the user-friendly name of a multipath device:
1. Run the pvs command to obtain the mapping between the physical volume and volume groups.
[root@node1 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/mpath/mpath18p1 vg06 lvm2 a- 5.00G 0
2. Run the ll /dev/mapper/ command to check the physical volume created for the multipath
device
[root@ Node1 ~]# ll /dev/mapper/
total 0
crw------- 1 root root 10, 63 Nov 16 12:41 control
brw-rw---- 1 root disk 253, 9 Nov 18 12:42 mpath18
Rescanning multipath devices 63