[pve-devel] [PATCH qemu-server v2] fix #3588: helper: consider NIC count for config-specific timeout

[pve-devel] [PATCH qemu-server v2] 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@proxmox.com>
---
v2: thanks @Fiona
 * fix typo
 * mention user reports in comment
 * use scalar
 * match for `^net\d{1,2}`, not just `^net`

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

diff --git a/PVE/QemuServer/Helpers.pm b/PVE/QemuServer/Helpers.pm
index 0afb6317..1888487e 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 $nic_count = grep { /^net\d{1,2}/ } keys %{$config};
+    $timeout += scalar ($nic_count * 5);
+
     return $timeout;
 }
 
-- 
2.39.5



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Re: [pve-devel] [PATCH qemu-server v2] fix #3588: helper: consider NIC count for config-specific timeout

[Fiona Ebner]

Am 21.11.24 um 16:13 schrieb Hannes Laimer:
> diff --git a/PVE/QemuServer/Helpers.pm b/PVE/QemuServer/Helpers.pm
> index 0afb6317..1888487e 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 $nic_count = grep { /^net\d{1,2}/ } keys %{$config};

I'd use \d+ like in other places.

> +    $timeout += scalar ($nic_count * 5);

I meant using scalar() around the grep, not here ;)


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