Slow Network Speeds in Containers in Guests

[alistairm]

Hi All,

We recently deployed Proxmox and have been pretty impressed so far. However we've run into an issue where the network speeds inside docker containers on guests are super slow (~50-100kB/s) whereas the Guest itself is getting about 40-50MB/s. The Host has a dual 100Gb link bonded in LACP back to our 100Gb TOR switch. The guests are running on a VLAN on that bond. As a test we took a single 1Gb link and created a VLAN on that for our guests and that seems to allow the containers to run at full speed, so not sure if it's something to do with the bond that's causing it.

We're Running PVE 8.2.7 on kernel 6.5.13-5-pve.
Guest OS is Ubuntu 22.04 with Docker as the container engine.

 

[Hannes Laimer]

Hey,

how is the packet loss? A bit of a wild guess, but is it possible the configured MTUs along your network don't always match up, other than that I can't really think of anything that might explain this, since the speed is fine for the VM itself. Have you tried different docker images, do different containers have different speeds?

 

[alistairm]

Hi @Hannes Laimer , I did consider the MTU, I tried it at 9000 as that's what our switch is set to and also at 1500 and 1400. Judging by general pings there doesn't seem to be any packet loss. I haven't tried different containers though. I'll give that a go and feedback.