On 3/21/25 04:21, Martin Kletzander wrote:
On Fri, Mar 21, 2025 at 08:29:30AM +0000, Daniel P. Berrangé via Devel wrote:
On Thu, Mar 20, 2025 at 09:36:15PM -0600, Jim Fehlig via Devel wrote:
On 3/20/25 17:07, Pavel Hrdina via Devel wrote:
Pavel Hrdina (6): tools: remove --parallel from virsh restore command tools: remote --parallel from virsh save command qemu: remove VIR_DOMAIN_SAVE_PARALLEL flag
Heh, I'm having one of those "why did I not realize that" moments :-).
IIRC, original we were using --parallel to decide whether to enable the new format, so --parallel with channels == 1 /was/ different from not setting --parallel at all.
Well, restore should figure out the format and save still has --image-format without which parallel save will fail (unless you have it set as default in a config). So I think this series is fine, at least it fixes the unit tests.
Agreed. The new format is enabled with --image-format parameter or by setting it as default in qemu.conf. And trying to use --parallel-channels without also specifying sparse fails as expected # virsh save --parallel-channels 4 test-vm /data/test-vm.sav error: Failed to save domain 'test-vm' to /data/test-vm.sav error: invalid argument: Parallel save is only supported with the 'sparse' save image format
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
But there's more to it than meets the eye.
There is also a check that the number of parallel channels is not lower than 1, for saving. Restoring happily takes parallel.channels=0 and (at least for non-sparse images) fails weirdly with:
error: Failed to restore domain from test.img error: Failed to open file 'test.img': No such file or directory
and the daemon reports:
2025-03-21 10:00:08.490+0000: 4076349: error : virFileIsSharedFSType:3598 : Invalid relative path 'test.img': Invalid argument 2025-03-21 10:00:08.490+0000: 4076349: error : virQEMUFileOpenAs:10448 : Failed to open file 'test.img': No such file or directory
even though the file exists. And it works without --parallel-channels, this only happens with --parallel-channels 0.
Hmm, I don't see this issue # virsh restore --parallel-channels 0 /data/test-vm.sav.sparse error: Failed to restore domain from /data/test-vm.sav.sparse error: invalid argument: number of parallel save channels cannot be less than 1 Could it be that you are using a relative path? Daniel and I just discussed this in patch1 of the V4 mapped-ram series. I'd provide a link, but https://lists.libvirt.org/archives/list/devel@lists.libvirt.org/ is currently down for me. I dropped that patch since we prefer absolute paths.
Last, but not least, our CI is broken with the patches here. And that is because now one cannot do save-image-edit, with both the new and the old format with:
error: failed to write header to domain save file '/home/nert/test.img': Bad file descriptor
I do see this issue and should have time to investigate it tomorrow. Regards, Jim