rsync backup stopped working Feb 29th

StephenB wrote:
Maybe open an online support case?

Did that, but not much help.

Anyway, I finally managed to reach a (temporary?) solution.

I had tried various reboots to no effect. Finally I read a couple of posts from ewok that said Jumbo Frames might be an issue. I set up a test backup job and tried it and noticed in syslog on the U2+

Mar  8 06:57:50 surire rsyncd[3864]: building file list
Mar  8 07:13:30 surire rsyncd[3864]: rsync: read error: Connection timed out (110)
Mar  8 07:13:30 surire rsyncd[3864]: rsync error: error in rsync protocol data stream (code 12) at io.c(760) [sender=3.0.8]

and netstat on that box said there was no connection on port 873, whereas in the NV+ it had a TCPIP connection in ESTABLISHED state...???

So, I then

- Disabled jumbo frames on both NAS boxes and rebooted both and performed the test backup again and it worked.
- I then re-enabled JF on the U2+, rebooted and did the test backup and it worked
- I then re-enabled JF on the NV+, rebooted and did the test backup and it worked

so, back to the state where both machines have JF enabled and rsync now works again - at least on the test backup. Let's see what happens tonight.