hello, 
i have problem for delete one snapshot.
i see the  error:
Due to partial snapshot removal, Snapshot 'Backup the VM' of VM 'vmname' now contains only the following disks: 'vmdiskname'.


Failed to delete snapshot 'Backup the VM' for VM 'vmname'.

information in db :
 imagestatus |           storage_pool_id            |          storage_domain_id           |            image_group_id            |              im
age_guid              |               parentid
-------------+--------------------------------------+--------------------------------------+--------------------------------------+----------------
----------------------+--------------------------------------
           1 | 77e24b20-9d21-4952-a089-3c5c592b4e6d | 6e5cce71-3438-4045-9d54-607123e0557e | bfb1e6b5-7a06-41e4-b8b4-2e237ed0c7ab | 1bb7bd08-5ee8-4
a3b-8978-c15e15d1c5e4 | 6008671c-2f9d-48de-94f3-cc7d6273de31
           4 | 77e24b20-9d21-4952-a089-3c5c592b4e6d | 6e5cce71-3438-4045-9d54-607123e0557e | bfb1e6b5-7a06-41e4-b8b4-2e237ed0c7ab | 6008671c-2f9d-4
8de-94f3-cc7d6273de31 | 00000000-0000-0000-0000-000000000000


output the script vm-disk-info.py 


 Disk bfb1e6b5-7a06-41e4-b8b4-2e237ed0c7ab (sd:6e5cce71-3438-4045-9d54-607123e0557e)
Warning: volume 1bb7bd08-5ee8-4a3b-8978-c15e15d1c5e4 is in chain but illegal
    Volumes:
        6008671c-2f9d-48de-94f3-cc7d6273de31
        1bb7bd08-5ee8-4a3b-8978-c15e15d1c5e4


output the  command md5sum :
volume :   1bb7bd08-5ee8-4a3b-8978-c15e15d1c5e4
4c05c8258ed5746da6ac2cdb80c8974e  1bb7bd08-5ee8-4a3b-8978-c15e15d1c5e4

ec74d4d8189a5ea24720349868ff7ab7  1bb7bd08-5ee8-4a3b-8978-c15e15d1c5e4

the volume change 

output the command md5sum :
volume: 6008671c-2f9d-48de-94f3-cc7d6273de31

86daf229ad0b65fb8be3a3de6b0ee840  6008671c-2f9d-48de-94f3-cc7d6273de31

86daf229ad0b65fb8be3a3de6b0ee840  6008671c-2f9d-48de-94f3-cc7d6273de31

the volume not change

Thanks.