Re: [PATCH v3 pve-qemu qemu-server 0/6] bypass host page cache for restore on zvol

["Lukas Sichert" <l.sichert@proxmox.com>]

On 2026-08-20 11:05, Christian Ebner <c.ebner@proxmox.com> wrote:

> This patch series skips writing to the host page cache for restores
> to zvols, with the intention to avoid potential I/O delay issues for
> other ZFS-backed VMs during page writeback on certain setups, as
> reported in enterprise support and reproduced internally.
>
> This patch series adds an optional no-cache parameter for pbs-restore
> command invocation, setting the BDRV_O_NOCACHE flag for the block
> device being restored to and sets `cache=none` for vma restores.

When I test patched debs on my testmachines I normally bump the version
with a local<x> suffigx. package_name_1.2.3 is deployed as
package_name_1.2.3+local1. When starting a restore with this and v2, I got
the error 'TASK ERROR: internal error: cannot check version of invalid
string 'unknown' at /usr/share/perl5/PVE/QemuServer/Helpers.pm line 104.'

Christian proposed the following diff off-list, which worked for me.

diff --git a/src/PVE/QemuServer/Helpers.pm b/src/PVE/QemuServer/Helpers.pm
index 5065a457..1ed48a3b 100644
--- a/src/PVE/QemuServer/Helpers.pm
+++ b/src/PVE/QemuServer/Helpers.pm
@@ -68,7 +68,7 @@ sub kvm_user_version {
     $kvm_mtime->{$binary} = $st->mtime;

     my $binary_version_re = qr/(\d+\.\d+(\.\d+)?)(\.\d+)?/;
-    my $package_version_re = qr/\(pve-qemu-kvm_(\d+\.\d+(\.\d+)?-\d+)\)/;
+    my $package_version_re = qr/\(pve-qemu-kvm_(\d+\.\d+(\.\d+)?-\d+)(\+[a-zA-Z0-9]+)?\)/;

     my $code = sub {
         my $line = shift;

I wouldn't consider this a blocker, but it would be a nice to have in a
potential next version.