PVE CPU overhead during PBS backup

[slapshot]

Hello, during VMs backup onto PBS server we are seeing a lots of use of Pve 7.2 CPU, sometimes over 100%.

Is there a way to move a bit of this overhead on PBS server or having some optimizations to reduce it ?

Thank you

 

[dcsapak]

the client (in this case pve) must calculate the checksum + compress + possibly encrypt the data before it reaches the pbs, so that cannot be done there
what kind of cpu do you use? also what is the output of

proxmox-backup-client benchmark

on your pve ?

 

[slapshot]

what kind of cpu do you use? also what is the output of

It is a Xeon E-2234

proxmox-backup-client benchmark

This is the output:

proxmox-backup-client benchmark
SHA256 speed: 559.77 MB/s
Compression speed: 623.61 MB/s
Decompress speed: 883.04 MB/s
AES256/GCM speed: 1903.45 MB/s
Verify speed: 338.04 MB/s
┌───────────────────────────────────┬────────────────────┐
│ Name                              │ Value              │
╞═══════════════════════════════════╪════════════════════╡
│ TLS (maximal backup upload speed) │ not tested         │
├───────────────────────────────────┼────────────────────┤
│ SHA256 checksum computation speed │ 559.77 MB/s (28%)  │
├───────────────────────────────────┼────────────────────┤
│ ZStd level 1 compression speed    │ 623.61 MB/s (83%)  │
├───────────────────────────────────┼────────────────────┤
│ ZStd level 1 decompression speed  │ 883.04 MB/s (74%)  │
├───────────────────────────────────┼────────────────────┤
│ Chunk verification speed          │ 338.04 MB/s (45%)  │
├───────────────────────────────────┼────────────────────┤
│ AES256 GCM encryption speed       │ 1903.45 MB/s (52%) │
└───────────────────────────────────┴────────────────────┘

Thank you very much.

 

[dcsapak]

ok, is your pbs faster (or as fast) than this result (mostly the chunk verification speed is relevant)? if yes, then this is normal and you get 'maximum throughput' of what your cpu can handle