
Flooded WD
Shortly after installing our Dell Powervault 3200i iSCSI SAN we started running out of space. Anticipating the worse I ordered four more 600 GB drives to double our capacity to 2.2TB. Unfortunately, the Thailand Flood hit and we were out of luck. Those who live there had it far worse than our hard drive space issues. Many months, several unsuccessful orders at double the price, and increased pressure to start work on projects waiting on that space we finally secured the four drives we needed at pre-flood prices.
Installing the Drives into the SAN was as easy as; install into drive, enter configuration utility and make the extra space available. However, letting XenServer know that there is added space available was a little tricky, at the same time not difficult. The instructions that follow are adapted to our use from the Citrix XenServer support pages. We use several physical servers and Multi-pathing which required a few extra steps. We have XenServer 5.6 but the 5.5 works perfectly.
If you have resized the LUN on which a iSCSI or HBA SR is based, use the following procedures to reflect the size change in XenServer:
iSCSI SRs with software initiator
- Shut down all virtual machines on the SR.
- Enter Maintenance mode on all physical servers.
- Turn off Multi-pathing on all servers.
- Note the Universally Unique Identifier (UUID) of the Storage Repository. Use the xe sr-list command on the XenServer host and identify the SR by its name label.
- Identify the Physical Block Device (PBD) UUID corresponding to the SR. Use the following command on XenServer:
# xe sr-param-list uuid=|grep PBD
whereUUID> is the UUID of the SR noted in step 2.
- Unplug the Physical Block Device (PBD) corresponding to the Storage Repository.
# xe pbd-unplug uuid=
where <PBD UUID> is the UUID of PBD noted in step 3.
- Plug the PBD.
# xe pbd-plug uuid=
Note: In previous versions of XenServer, explicit commands were required to resize the physical volume group of iSCSI and HBA SRs. These commands are now issued as part of the PBD plug operation and are no longer required.
- Turn on Multi-pathing
- Exit Maintenance Mode
- Power on the Virtual Machines.