Re: [pve-devel] [PATCH qemu-server 2/2] backup: use dirty-bitmap for PBS only if supported by QEMU

[Thomas Lamprecht <t.lamprecht@proxmox.com>]

On 08.07.20 10:42, Stefan Reiter wrote:
> If 'query-proxmox-support' is not known to QEMU, assume that no other
> features are supported either.
> 
> Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
> ---
> 
> Does not require any version bumps, since it handles failure gracefully.
> 
>  PVE/VZDump/QemuServer.pm | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/PVE/VZDump/QemuServer.pm b/PVE/VZDump/QemuServer.pm
> index 567088c..3c2a334 100644
> --- a/PVE/VZDump/QemuServer.pm
> +++ b/PVE/VZDump/QemuServer.pm
> @@ -443,6 +443,8 @@ sub archive_pbs {
>  	    die "interrupted by signal\n";
>  	};
>  
> +	my $qemu_support = eval { mon_cmd($vmid, "query-proxmox-support") } // {};

can we not fall back and instead use undef here to error out with a nice
"does not support PBS at all" message?

> +
>  	my $fs_frozen = $self->qga_fs_freeze($task, $vmid);
>  
>  	my $params = {
> @@ -453,11 +455,13 @@ sub archive_pbs {
>  	    password => $password,
>  	    devlist => $devlist,
>  	    'config-file' => $conffile,
> -	    'use-dirty-bitmap' => JSON::true,
>  	};
>  	$params->{fingerprint} = $fingerprint if defined($fingerprint);
>  	$params->{'firewall-file'} = $firewall if -e $firewall;
>  
> +	$params->{'use-dirty-bitmap'} = JSON::true
> +	    if $qemu_support->{'pbs-dirty-bitmap'};
> +
>  	$params->{timeout} = 60; # give some time to connect to the backup server
>  
>  	my $res = eval { mon_cmd($vmid, "backup", %$params) };
>