I was playing around with raspiBackup.sh (https://www.linux-tips-and-tricks.de/en/quickstart-rbk/) on my 2nd pi as I successfully use it on my 1st pi which runs Raspbian, but I'm running into trouble getting it running on pi3b+ with ubuntu server (ubuntu-18.04.2-preinstalled-server-arm64+raspi3.img.xz)

I did do a succesful rsync backup to attached usb key to rule out it's the script malfunctioning and this worked out no problem.

However when trying to do the same onto a nfs share (mounted via autofs) the pi stalled and monitoring the nfs share on the host didn't show any files being copied over past the first few hundred of megabytes.

Then I did some testing and found out that while my link speed is reported as 1000Mbit, I could only copy 5GB file from the nfs server to the pi at ~10-13MB/s. This might be due to sdcard although I'm using the samsung evo 64gb one supposed to have 90read/30write iirc.

However, when trying to copy the 5GB file back to the nfs share the pi started copying at around 10-13MB/s again, and stalled within first 300-ish MBs and I captured this in dmesg: https://turbomrak.ddns.net/s/tE8cApNQ7nKiHTT

dd backup copied a bit, hung, copied a bit, hung and then after it took 3 hours to copy 1gb I gave up and rebooted the pi.

using wifi achieves same results more slowly.

Is this something wrong with my installation or the pi or the system ?

  • You will be bottlenecked by write speed to disk on the server providing the NFS, as well as the fact that RPi3 gigabit is not really full gigabit, as it's sharing the USB lane to the SoC. – dobey Jun 25 at 19:21
  • I'm aware of the rpi nic limits, but I'd still expect more than 10-13 MB/s. No point in gigabit if that's top. The nfs server is a freenas with 48GB ecc ram on quad 3.3ghz xeon, I recently copied continuously ~20TB to it with sustained speeds between ~800mbit, and it handles this same procedure from different pi running Raspbian without a hitch. I'm not talking continuous slow transfer, I'm talking system hangs in excess of 30mins at times, producing error stack traces in dmesg. I think this cannot be in any way intended behaviour. It also only happens when writing to server, reading is fine. – C.G.B. Spender Jun 25 at 19:59

I ended up switching to raspbian buster and there the networking works as expected. There might be a way to make the ubuntu server networking work on pi properly but I have nor time nor knowledge to do anything about it.

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