When increasing the size of iSCSI SR, this change is not reflected by default within XenServer. To resolve this, follow the procedure outlined here. I am including one minor change to original article CTX126473 (addition of your host-uuid in step 3):
Note: This procedure does not cover any activities that must be performed on the storage array itself. Consult the storage array documentation for information on modifying the size of a LUN. Also, the LUN size modifications must be completed prior to performing the instructions below. Note also that this example applies to a XenServer iSCSI Storage Repository only.
Note: UUIDs for Master XenServer and target SR can also be found within XenCenter – command line for this is not necessarily required to obtain these.
Steps:
Identify the SR Universally Unique Identifier (UUID)
#xe sr-list type=lvmoiscsi name-label=<Name of your SR> –minimal
Identify the device this SR is using:
#pvs | grep <UUID from step 1>
Identify the iSCSI target name to rescan:
#xe pbd-param-get uuid=$(xe pbd-list sr-uuid={UUID from step 1} –minimal host-uuid={master UUID}) param-name=device-config param-key=targetIQN
Extract the content of the image
# iscsiadm -m node –targetname < targetIQN from step 3> -R
Update the Physical Volume size:
# pvresize /dev/<device from step 2>
Update the SR size:
#xe sr-scan uuid=<UUID from step 1>
Reference:
https://support.citrix.com/article/CTX126473
https://forums.citrix.com/thread.jspa?threadID=283888&tstart=0