Previously, when creating snapshots the backing volume reference included an image directory component. Each time a snapshot was merged, the image directory component of the backing volume reference was duplicated until the backing volume reference became too long. In this state the image could not be used. Now, since all volumes of an image always reside in the same directory, the image directory component has been removed from new backing volume references. Now the backing volume references do not grow in length after snapshots are merged.
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHBA-2016:1365
Steps: 1. Created a VM with 1 Disk, Raw (iSCSI preallocated) 2. Snapshot it 3 times: (Base) [A] <- [B] <- [C] <- [D] (Leaf) 3. Removed B The backing file is the image id: [root@blond-vdsf c51bf8d8-c508-4f42-8857-5a8d2a7d3774]# pwd /rhev/data-center/mnt/blockSD/2fdf22e8-b272-4795-a940-34ecd57af2c6/images/c51bf8d8-c508-4f42-8857-5a8d2a7d3774 [root@blond-vdsf c51bf8d8-c508-4f42-8857-5a8d2a7d3774]# tree . ├── 16ab7f99-966b-4620-b7ef-aaed31e3d83f -> /dev/2fdf22e8-b272-4795-a940-34ecd57af2c6/16ab7f99-966b-4620-b7ef-aaed31e3d83f ├── 77f9a5c0-a628-4772-a9b3-512758b318d3 -> /dev/2fdf22e8-b272-4795-a940-34ecd57af2c6/77f9a5c0-a628-4772-a9b3-512758b318d3 └── f42045f2-d5f7-4c7d-85e7-bc967f6f1c78 -> /dev/2fdf22e8-b272-4795-a940-34ecd57af2c6/f42045f2-d5f7-4c7d-85e7-bc967f6f1c78 0 directories, 3 files [root@blond-vdsf c51bf8d8-c508-4f42-8857-5a8d2a7d3774]# qemu-img info 16ab7f99-966b-4620-b7ef-aaed31e3d83f image: 16ab7f99-966b-4620-b7ef-aaed31e3d83f file format: qcow2 virtual size: 1.0G (1073741824 bytes) disk size: 0 cluster_size: 65536 backing file: f42045f2-d5f7-4c7d-85e7-bc967f6f1c78 backing file format: qcow2 Format specific information: compat: 0.10 refcount bits: 16 ====================== The VM is fully operational. ====================== Verified using: vdsm-4.17.31-0.el7ev.noarch rhevm-3.6.7.2-0.1.el6.noarch