Epyc VM to VM networking slow
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@olivierlambert said in Epyc VM to VM networking slow:
If I wouldn't be convinced to fix it, I wouldn't throw money & time to solve the problem
I think everyone knows this. Nevertheless, it is frustrating anyone if it becomes a bottleneck.
I am curious, do we know if this happens on Xen systems, or if it happens on xcp-ng systems where Open vSwitch is not used?
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It happens on all Xen version we tested, the issue is clearly inside the Xen Hypervisor, and related on how the netif calls are triggering something slow inside AMD EPYC CPUs (not even Ryzen ones)
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@manilx do you use NBD for delta backups ?
in the advanced settings -
@florent Florent, yes I do use NBD for all backups. And checking the backup log of the completed jobs I see that NBD is being used.
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@manilx said in Epyc VM to VM networking slow:
@florent Florent, yes I do use NBD for all backups. And checking the backup log of the completed jobs I see that NBD is being used.
could you test disabling NBD ?
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@manilx Running a test backup, one with NBD and then again without. Will report asap.
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@florent Result of backup tests:
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It may not be of any help, but wanted to add a little bit of info this anyway.
I'm seeing the same results on a set of Ubuntu 22.04 in my Threadripper based cluster. I didn't expect to see different results, since Threadripper is really just EPYC with some stuff turned off.
Specifically tested on a 16 core 1950X host and a 32 core 3970X host, both with 8 vCPUs on each VM, they topped out at 8 gigabit like most others are seeing.
Figured I'd add it in here.
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Thanks! We didn't test on threadrippers yet, so it's useful info
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