Problems

Common problems you might encounter

It keeps asking for my SSH password

You forgot to setup automatic login via SSH keys, look in the example how to do this.

"cannot receive incremental stream: invalid backup stream"

This usually means you've created a new snapshot on the target side during a backup. If you restart zfs-autobackup, it will automaticly abort the invalid partially received snapshot and start over.

"cannot receive incremental stream: destination has been modified since most recent snapshot"

This means files have been modified on the target side somehow.

• You can use --rollback to automatically rollback such changes.
• Try using --clear-mountpoint, so the filesystems wont be mounted. Mounting will sometimes lead to changes since it might have to create mount-point directories in filesystems. --clear-mountpoint only affects newly received filesystems, so you might have to set the canmount=noauto property on existing target filesystems yourself.
• Set the readonly property of the target filesystem to on. This prevents all modifications on the target side. Note that readonly prevents changes to the CONTENTS of the dataset directly. Its still possible to receive new datasets and manipulate properties etc.

"internal error: Invalid argument"

In some cases (Linux -> FreeBSD) this means certain properties are not fully supported on the target system.

Try using something like: --filter-properties xattr or --ignore-transfer-errors.

zfs receive fails, but snapshot seems to be received successful.

This happens if you transfer between different Operating systems/zfs versions or feature sets.

Try using the --ignore-transfer-errors option. This will ignore the error. It will still check if the snapshot is actually received correctly.

"cannot receive incremental stream: kernel modules must be upgraded to receive this stream."

This happens if you forget to use --encrypt, while the target datasets are already encrypted. (Very strange error message indeed)

"dataset is busy"

If you try to destroy a snapshot and its busy, there might be multiple reasons, but dont forget to check if the snapshot has holds with:

zfs holds zpool/fs1@snapshot1

Release it with zfs release.

Use --no-holds in zfs-autobackup if you dont want to use holds.

Other problems

Feel free to ask questions about zfs-autobackup on our issue tracker at https://github.com/psy0rz/zfs_autobackup/issues

For more general questions go to the excellent subreddit at https://reddit.com/r/zfs