gmirror device numbers

[Toomas Aas]

Hello!

I have a server with gmirror volumes. Backup of this server is being done 
with Amanda, which uses GNU tar and its --listed-incremental option 
(snapshot files) in order to do incremental backups.

It seems that gmirror devices get a different 'device number' on each boot 
(each time the gmirror is created). Since the device number is stored in 
GNU tar's snapshot file, it effectively means that after rebooting GNU tar 
sees all files as having been changed since previous backup. This causes 
huge incremental backups.

Is there a way to force a gmirror device to have a 'fixed' device number?

-- 
Toomas Aas