I cannot access the log file, so I’m guessing that your node probably stops due to insufficient I/O operations left. The check that the node performs tests whether it is possible to read or write a small file within one minute—and failing to do so will shut down the node. You can tune parameters responsible for this check.
Some other ideas to reduce the interaction of the copy operation and node’s are:
- running your rsync under
ionice(though not sure if this will help on Synology) with sth likeionice -c Idle rsync …, - if you have a lot of RAM in your Synology unit (probably at least 12 GB in your case), it will help to use the rsync’s
--no-inc-recursiveflag; but if you don’t, this flag will slow down the copy operation even more, - temporarily disabling uploads by reducing your disk space allocation,
- if you estimate the time left for the copy to run to be below few days, you can probably turn off the node altogether—downtime of few a days is recoverable, though the satellite might migrate some small amounts of data to other nodes.