HP 3PAR RedHat and Oracle Linux Implementation Guide
2. Run the showvlun command on the HP 3PAR StoreServ Storage using the output above
(minus first digit).
# showvlun -lvw -a |grep -i 50002ac001b40031
0 testvlun 50002AC001B40031 redhathost 2100001B321A0C63 0:4:1 host
0 testvlun 50002AC001B40031 redhathost 2101001B323A0C63 1:5:1 host
3. On the iSCSI host, run ls /dev/mapper.
# ls /dev/mapper
350002AC0004B0079
4. On the iSCSI host, run showvlun -lvw -a |grep -i <LUN>.
# showvlun -lvw -a |grep -i 50002ac0004b0079
0 testvlun 50002AC0004B0079 redhathost iqn.1994-05.com.redhat:a3df53b0a32d 1:3:1 host
0 testvlun 50002AC0004B0079 redhathost iqn.1994-05.com.redhat:a3df53b0a32d 0:3:1 host
Creating Veritas Volume Manager Devices
If the Veritas Volume Manager is being used for multipathing, and new VLUNs are exported from
the storage server, complete the following steps to add new VLUNs without disrupting the I/O on
the existing VLUNs:
1. Add the new exported VLUN using any of the Discovery methods.
2. After verifying that the new VLUN is detected and the device instance is created, force the
Veritas layer to scan for new devices.
# vxdctl enable
3. Check that the new devices are seen by the Veritas Volume Manager. After device initialization,
the status will change from being in an error state to being online.
# vxdisk list
DEVICE TYPE DISK GROUP STATUS
3PARDATA1_0 auto:cdsdisk testdg testdg online
3PARDATA1_1 auto - - error
The VLUNs discovered on the Linux host should be labeled using the Linux fdisk command
before they can be used by the Veritas Volume Manager.
If disks are admitted to the Volume Manager, never use the raw device paths /dev/sdX for
performing I/O, and instead use Veritas volume device paths /dev/vx/.
Removing a Storage Volume from the Host
Use one of the two following methods to remove a storage volume from the host if using
Device-mapper.
• Method 1
Issue the following commands:
# kpartx -d /dev/mapper/<device node>
# dmsetup remove <device node>
# echo "1" > /sys/class/scsi_device/<device instance>device/delete
122 Modifying HP 3PAR Devices on the Host