[IAEP] Restoring journals on newer versions of Sugar

[Bernie Innocenti]

Answering your question on IRC:

 <christophd> hi all
 <christophd> I've got a question related to Journal backup/restore: is
  it realistically possible to get Journal entries created on 8.2 to
  11.1.2 with the help of dsd_'s scripts or other ways?

Yes. If you make a tarball from the contents of
~/.sugar/default/datastore created on an older Sugar release, then
unpack it in the same location on a newer release, the datastore will
automatically upgrade it to the current format.

In fact, the jorunal backup/restore GUI in Dextrose [1] is a distant
cousin of Daniel Drake's scripts. It also performs backups/restores to
the schoolserver using rsync, which is what most users do across
upgrades.

Getting all the little details right wasn't easy, we had to do a lot of
testing in various scenarios, and there are still a few corner cases
that we haven't taken care of. For example, if the next version of the
OS grows bigger, restoring a very large datastore would fail.

The next step would be allowing users to browse remote datastores on the
schoolserver and restore individual files. This isn't as hard as it may
sound, because the on-disk format of the schoolserver is just an rsync
of a regular datastore, and the user has full ssh access to it, so it
would be easy to access it with FISH [2].

[1] http://wiki.sugarlabs.org/go/Features/Backup_and_Restore
[2] http://en.wikipedia.org/wiki/Files_transferred_over_shell_protocol

-- 
Bernie Innocenti
Sugar Labs Infrastructure Team
http://wiki.sugarlabs.org/go/Infrastructure_Team