Cleaning up orphan VHDs when XenServer storage migrations fail

^{Created: 2018-09-10 23:11:16 | Last modified: 2020-05-22 01:16:06} ^{| By: Nova}
^{Access: Read}^{| Visibility: Public}^{| Views: 991}^{| Rating: +2}^{| Tags: xenserver linux vhd vdi}
When a storage migration with XenServer fails, it can cause orphan VHD to be left on a particular storage repository

When performing a storage migration with XenServer, if the storage migration fails it can leave orphan VHDs on the storage repository filling it up. These VHDs need to be removed from XenServer to free up space in the storage repository. To do this, you need to get a list of all of the VDIs, then check each one to see if it is attached to a virtual machine (VM), if it isn't then you delete it.

Get a list of all of the VDIs for a particular storage repository, I copied this to a notepad

xe vdi-list sr-uuid=

#Example
xe vdi-list sr-uuid=adbdb53f-ef8f-4acc-d1c5-a53f0e15119e

#Example2 - grep with before and after lines, 821dc416 is taken from doing a SR scan. 
#Check all VDIs in a tree before deleting (go bottom of the tree up)
xe vdi-list sr-uuid=adbdb53f-ef8f-4acc-d1c5-a53f0e15119e | grep -B 4 -A 4 821dc416


uuid ( RO)                : 821dc416-f61b-415c-a4e0-0457a5abfad5
          name-label ( RW): VM1_SR
    name-description ( RW):
             sr-uuid ( RO): adbdb53f-ef8f-4acc-d1c5-a53f0e15119e
        virtual-size ( RO): 1202590842880
            sharable ( RO): false
           read-only ( RO): false


uuid ( RO)                : d4bff1d5-cdca-4996-a347-7036437515f4
          name-label ( RW): VM2_SR
    name-description ( RW):
             sr-uuid ( RO): adbdb53f-ef8f-4acc-d1c5-a53f0e15119e
        virtual-size ( RO): 107374182400
            sharable ( RO): false
           read-only ( RO): false

Check if VDI is connected to a VM

xe vbd-list vdi-uuid=

#Example - In this case you would NOT destroy VDI
xe vbd-list vdi-uuid=821dc416-f61b-415c-a4e0-0457a5abfad5

uuid ( RO)             : 0016efa0-a23e-5f13-0dc2-2ced08bb3e16
          vm-uuid ( RO): 29d99bc4-7ded-2de0-317e-ccca01df2c04
    vm-name-label ( RO): VM1
         vdi-uuid ( RO): 6d720d19-c935-4720-a7ea-3458174629c0
            empty ( RO): false
           device ( RO): xvdb

#Example - In this case you would destroy the VDI
xe vbd-list vdi-uuid=d4bff1d5-cdca-4996-a347-7036437515f4

If the above doesn't return anything, you are safe to delete the VDI

xe vdi-destroy uuid=

#Example
xe vdi-destroy uuid=d4bff1d5-cdca-4996-a347-7036437515f4

Once complete, check your storage repository size in XenServer and you should notice its usage has dropped