Openfiler NAS 2.3, when used to provide iSCSI storage repositories to XCP 1.6 pools, needs some tweaking to allow the SRs to re-connect after the NAS is rebooted. Without the tweak, XenCenter will show the SR as broken/unplugged and ‘xe pbd-list’ will show the SR as detached. XCP will be able to scan and detect the iSCSI targets, but not find any LUNs.
The issue is discussed and solved in this forum post, which I am summarizing here for future reference. Here is my summary of the problem:
- Openfiler uses LVM to back iSCSI targets
- XCP uses LVM to back volumes on storage repositories
- When you create XCP volumes on an iSCSI SR, an LVM-inside-LVM scenario is created
- Openfiler activates *all* logical volumes on boot
- Because all volumes are ‘claimed’ by Openfiler, none are available for XCP
The solution, as described in the forum, is to comment-out lines 333-337 of /etc/rc.sysinit on the Openfiler box and reboot. The iSCSI SR can then be re-attached or re-created (via XenCenter, xsconsole, or manually via xe). Note that re-creating will destroy/re-format the SR, so re-attach if possible.