Red Hat Bugzilla – Bug 1521163
[RFE] blkid can identify magic number and UUID of VDO volume
Last modified: 2018-04-10 13:28:02 EDT
Description of problem: VDO is a device mapper target with deduplication and compression features. Until recently VDO did not have a magic number or UUID. blkid support for VDO is needed, so utilities using blkid can be informed that the a given storage device is being used by VDO. Version-Release number of selected component (if applicable): How reproducible: 100% can't identify VDO volumes Create a VDO volume Steps to Reproduce: 1. vdo create --name=vdo1 --device=/dev/sdb --vdoLogicalSize=10T 2. # blkid /dev/sdb Actual results: # blkid /dev/sdb # <nothing> Expected results: # blkid /dev/sdb # /dev/sdb: UUID="<string>" TYPE="VDO" Additional info:
The magic number is the first 8 bytes, with value 'dmvdo001' of the volume; the UUID is the 16 bytes starting 40 bytes into the volume. I could probably draw up quickly a superblocks/vdo.c if desired.
(In reply to Sweet Tea Dorminy from comment #3) > I could probably draw up quickly a superblocks/vdo.c if desired. Thanks! It would be nice. The ideal solution is to prepare a patch for upstream tree: https://github.com/karelzak/util-linux I'll backport it to RHEL7. See also libblkid/src/superblocks/lvm.c where are another DM targets, maybe we can add DM_VDO there. It would be also nice to have a test image with the superblock (just dd(1) first sectors from the device).
https://github.com/karelzak/util-linux/pull/547
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-2018:0936