PBS backups slow from a specific Proxmox server


Well-Known Member
Aug 15, 2018
I have 3 Proxmox servers which are NOT configured as a cluster, and a PBS.

All 4 have access to the network where backup traffic is send.

All 4 have 1gbit cards for the network and running iperf across them confirms that im getting around 1gbps.

2 of the Proxmox servers backup the LXCs and VMs to PBS quite quickly at no less that 15.88 MiB/s.

The third PVE has two LXCs but seems to backup very slowly at around 2.86 MiB/s.

Are there any further tests I can run to identify where the bottleneck might be?
how big are the files on average and how fast can you read the files from disk?
if you are not network limited, and not limited on the target side, you are most probably limited on the source storage side

e.g. if you have many small files on a hdd, this severely impacts performance, since hdds only can do ~80 iops for 4k ( see e.g. https://en.wikipedia.org/wiki/IOPS )


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