Re: [PULL 09/11] migration: file URI

[Fabiano Rosas <farosas@suse.de>]

Juan Quintela <quintela@redhat.com> writes:

> From: Steve Sistare <steven.sistare@oracle.com>
>
> Extend the migration URI to support file:<filename>.  This can be used for
> any migration scenario that does not require a reverse path.  It can be
> used as an alternative to 'exec:cat > file' in minimized containers that
> do not contain /bin/sh, and it is easier to use than the fd:<fdname> URI.
> It can be used in HMP commands, and as a qemu command-line parameter.
>
> For best performance, guest ram should be shared and x-ignore-shared
> should be true, so guest pages are not written to the file, in which case
> the guest may remain running.  If ram is not so configured, then the user
> is advised to stop the guest first.  Otherwise, a busy guest may re-dirty
> the same page, causing it to be appended to the file multiple times,
> and the file may grow unboundedly.  That issue is being addressed in the
> "fixed-ram" patch series.
>
> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
> Tested-by: Michael Galaxy <mgalaxy@akamai.com>
> Reviewed-by: Michael Galaxy <mgalaxy@akamai.com>
> Reviewed-by: Fabiano Rosas <farosas@suse.de>
> Reviewed-by: Peter Xu <peterx@redhat.com>
> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> Reviewed-by: Juan Quintela <quintela@redhat.com>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> Message-ID: <1694182931-61390-2-git-send-email-steven.sistare@oracle.com>

Juan, FYI we have tests for this feature already reviewed and ready to
merge:

[PATCH v5 0/6] migration: Test the new "file:" migration
https://lore.kernel.org/r/20230712190742.22294-1-farosas@suse.de