action #38822

Qemu: Could not open backing file: Cannot reference an existing block device with additional options or a new filename

Added by rpalethorpe over 1 year ago. Updated over 1 year ago.

Status:ResolvedStart date:25/07/2018
Priority:UrgentDue date:
Assignee:rpalethorpe% Done:

0%

Category:-
Target version:Done
Difficulty:
Duration:

Description

When trying to revert to a snapshot QEMU dies with the following error or something similar:

-blockdev driver=qcow2,node-name=hd0-overlay1,file=hd0-overlay1-file,cache.no-flush=on,backing=hd0: Could not open backing file: Cannot reference an existing block device with additional options or a new filename

The backing file is the hd0 block device which is specified on the command line. Possibly we should not specify block devices used as backing files on the command line and just allow them to be read from the overlay file. It is not clear what the expected usage is.


Related issues

Copied from openQA Project - action #38813: Qemu backend rewrite fallout Resolved 25/07/2018

History

#1 Updated by rpalethorpe over 1 year ago

#2 Updated by rpalethorpe over 1 year ago

Looking at qemu/block.c I suspect we can only specify options (e.g. cache.no-flush=on) on one of the blockdevices in the chain.

#4 Updated by rpalethorpe over 1 year ago

  • Status changed from New to Feedback
  • Assignee set to rpalethorpe

#5 Updated by rpalethorpe over 1 year ago

  • Status changed from Feedback to Resolved

#6 Updated by szarate over 1 year ago

  • Target version changed from Current Sprint to Done

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