cannot receive incremental stream: destination foo has been modified

[Nikos Vassiliadis]

Hi everybody,

 From time to time my backup scripts break because "zfs recv"
complains that a destination filesystem is modified (1). That should
not be the case as the filesystems in the backup server are not
mounted and "zfs receive" is always using the -u arg which also
suggests that filesystems won't be mounted at the receiving side.

Of course this is easily fixed with the help of -F on the receiving
side which forces a rollback to the most recent snapshot. It just
doesn't feel correct to blindly force it every time.

I haven't noticed when exactly this happens, maybe it's related
to a network failure while sending. I am not sure what would modify
a filesystem... It happens maybe once every few months.

The commands doing the backups are these:
sending:> zfs send -R -i @2018-02-24_12.30.00--10d 
storage at BACKUP-2018-02-24_14.30.49--1m
receiving:> zfs recv -u storage

Has anybody else seen this? Am I doing something wrong?

1:
> cannot receive incremental stream: destination storage/home/foo has been modified
> since most recent snapshot

Thanks!
Nikos