[pve-devel] [PATCH qemu-server v3] fix #3588: helper: consider NIC count for config-specific timeout

[Hannes Laimer]

There have been some reports about `qm start` timeouts on VMs that have a
lot of NICs assigned.
This patch considers the number of NICs when calculating the config-specific
timeout. Since the increase in start time is linearly related to the number
of NICs, a constant timeout increment per NIC was chosen.

Signed-off-by: Hannes Laimer <h.laimer at proxmox.com>
---
changes since v3:
 * move scalar() to wrap grep...
 * match against `\d+` instead of `\d{1,2}`

 PVE/QemuServer/Helpers.pm | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/PVE/QemuServer/Helpers.pm b/PVE/QemuServer/Helpers.pm
index 15e2496c..72a46a0a 100644
--- a/PVE/QemuServer/Helpers.pm
+++ b/PVE/QemuServer/Helpers.pm
@@ -167,6 +167,15 @@ sub config_aware_timeout {
 	$timeout = 150;
     }
 
+    # Some testing showed that adding a NIC increased the start time by ~450ms
+    # consistently across different NIC models, options and already existing
+    # number of NICs.
+    # So 10x that to account for any potential system differences seemed
+    # reasonable. User reports with real-life values (20+: ~50s, 25: 45s, 17: 42s)
+    # also make this seem a good value.
+    my $nic_count = scalar (grep { /^net\d+/ } keys %{$config});
+    $timeout += $nic_count * 5;
+
     return $timeout;
 }
 
-- 
2.39.5