This article describes how to reattach LVM or a local Storage repository on XenServer. The XenServer database has become corrupt or your XenServer does not see the local SR.

Instructions

• Do a pvscan to get the Universally Unique Identifier (UUID) of an existing SR on a local disk. In this example uses UUID 39baf126-a535-549f-58d6-feeda55f7801:

  pvscan

Output:

PV /dev/sda3 VG VG_XenStorage-39baf126-a535-549f-58d6-feeda55f7801 lvm2 [66.87 GB / 57.87 GB free]
Total: 1 [66.87 GB] / in use: 1 [66.87 GB] / in no VG: 0 [0 ]

Note the output above, the VG name of the local drive /dev/sda3 is VG_XenStorage-39baf126-a535-549f-58d6-feeda55f7801 . The VG name contains the SR UUID that resides on this storage media. In this case, the UUID is 39baf126-a535-549f-58d6-feeda55f7801.

• Introduce the SR with the following command:

  xe sr-introduce uuid=39baf126-a535-549f-58d6-feeda55f7801 type=lvm name-label=”Local storage” content-type=user

  This command sets up database records for the SR named “Local storage”

• Locate the SCSI ID of the device or partition where the SR data is stored:

  ls -l /dev/disk/by-id/

Output:

total 0
lrwxrwxrwx 1 root root 9 Jan 15 09:44 scsi-SATA_ST3500320AS_9QM13WP2 -> ../../sdb
lrwxrwxrwx 1 root root 10 Jan 15 09:44 scsi-SATA_ST3500320AS_9QM13WP2-part1 -> ../../sdb1
lrwxrwxrwx 1 root root 9 Jan 15 09:44 scsi-SATA_ST380815AS_6QZ5Z1AM -> ../../sda
lrwxrwxrwx 1 root root 10 Jan 15 09:44 scsi-SATA_ST380815AS_6QZ5Z1AM-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Jan 15 09:44 scsi-SATA_ST380815AS_6QZ5Z1AM-part2 -> ../../sda2
lrwxrwxrwx 1 root root 10 Jan 15 09:44 scsi-SATA_ST380815AS_6QZ5Z1AM-part3 -> ../../sda3

_In this case, the SCSI ID of the device /dev/sda3 is scsi-SATA_ST380815AS_6QZ5Z1AM-part3.

Notate the device name to use in the next command, where a PBD (physical block device – a connector between the XenServer host and the SR) is created._

• Run the xe host-list command to find out the host UUID for the local host:

  xe host-list

uuid ( RO) : 83f2c775-57fc-457b-9f98-2b9b0a7dbcb5
name-label ( RW): xenserver1
name-description ( RO): Default install of XenServer

• Create the PBD using the device SCSI ID, host UUID and SR UUID detected above:

xe pbd-create sr-uuid=39baf126-a535-549f-58d6-feeda55f7801 device-config:device=/dev/disk/by-id/scsi-SATA_ST380815AS_6QZ5Z1AM-part3 host-uuid=83f2c775-57fc-457b-9f98-2b9b0a7dbcb5

Afterward, it displays: aec2c6fc-e1fb-0a27-2437-9862cffe213e

• Attach the PBD created with xe pbd-plug command:

  xe pbd-plug uuid=aec2c6fc-e1fb-0a27-2437-9862cffe213e

In the end, you now have reattach LVM to the XenServer host and be visible in XenCenter.

Source: Original Article from Citrix http://support.citrix.com/article/CTX121896