ZFS send/receive Backwards compatibility information

Question

In Solaris 10 6/06 man page for zfs send, it says

The format of the stream is evolving. No backwards compatibility is guaranteed. You may not be able to receive your streams in future versions of ZFS.

Now that was 5 years ago. Now I want to know if Solaris 11 Express (latest) can receive streams from Solaris 10 6/06? I would like to have a backup server on the latest version of Solaris if possible. If not, then I want to know which version caused the incompatibility?

The 6/06 zpool upgrade -v shows the last version as number 3.

This article is related to OpenSolaris might answer the question but I do not know how the Nevada builds correspond to regular Solaris: http://hub.opensolaris.org/bin/view/Community+Group+on/2008042301

I would most appreciate if there was a way to translate old ZFS streams to the new format, so I don't have to be held back to an old version in this project?

Answer 1

AFAIK, you should be able to receive these streams on a Solaris 11 Express server.

ZFS pool version 3 correspond to nevada build 42 (see http://hub.opensolaris.org/bin/view/Community+Group+zfs/3 ), i.e. postdates the incompatibility issue introduced by build 36.

Incompatible streams are the ones from nv27a (first ZFS release) to build 35, they all predate Solaris 10 6/06.

In any case, while I don't think there is a way to directly convert a stream from one format to another, you can receive a ZFS stream, upgrade the resulting file system to an upper version and send it afterwards. That would make the stream incompatible with the original sender which might not be the best backup strategy.

If your goal is to be able to fully restore a file system (i.e. receive the backup stream back to the original server), it doesn't matter what ZFS version the backup server supports. It might not even support ZFS at all as this stream can just be stored as a plain file.