@pierrebrunet Hi!
I'm on vacation now, so sorry for the delay. In the meantime I've been analyzing these issues and it seems these are somewhat expected and still happen with minpartsize set to 100M.
My next step is to increase the AWS_MAX_ATTEMPTS from the default 3 attempts to 10. This might reduce the number of failed VMs and avoid the need to retry the full VM backup.
From AI research, it seems rclone uses 10 attempts instead of the AWS SDK default.
Here are some stats of my weekly full backup to B2:
"00 Weekly Full Backblaze" ran xxxx → xxxxx — 34.1 hours total, moving ~2.86 TiB across 89 VMs. Final status: failure (more on that below, because it's misleading) -> this is related to XO reporting the backup as a failure even though the follow up retry succeded which is a known issue.
Every one of the 7 first-attempt errors shows attempts: 3 in the SDK metadata — the default budget was exhausted in all cases -> 7 of 89 VMs failed on the initial attempt.
Error mix: 5× Backblaze InternalError 500, 1× ECONNRESET, 1× EPIPE
The 7 failed first attempts burned ~7.1 hours of cumulative transfer time
Even though XO does not expose AWS_MAX_ATTEMPTS parameter I might be able to set it using an environment variable. I'll give a try when I'm back at the office.
Tks,
Pedro
