xbiancopy never stop

[Nachteule]

The data is copied via

btrfs send | btrfs receive

and if this operation fails with error, E_COPY_DATA will returned as error

You can look in the file /usr/sbin/btrfs-auto-snapshot and search for this error

BTW, I am currently also struggling with the backup function for me, the kswapd0 process (the process occupies 100% of one core) totally slows down the backup. I have noticed this for about 6 weeks.

Where this suddenly comes from I can not explain, probably by newer kernel versions.

However, I have already found the reason:

It's the line MY_MIN_FREE_KBYTES=75000 in the file /usr/sbin/btrfs-auto-snapshot. If you reduce the value to 22500, the kswapd0 doesn't go crazy anymore
This value is used for setting /proc/sys/vm/min_free_kbytes while backup is running.

Of course this makes no sense since 75000 means only 75MByte, which is a ridiculous value with 4 or even 8GB of system memory. however, the value has a significant impact. Maybe a kernel bug in newer versions

Perhaps, changing this value will help you too