dumping file system subtree (/var)

[Warren Block]

On Thu, 7 Jun 2012, Gary Aitken wrote:

> When I originally set up my SSD, the stuff I was following indicated 
> there was no need to put anythng on a separate filesystem.  I'm now 
> trying to build a backup system on a usb drive and I want a separate 
> /var and /tmp.
>
> I had originally set the nodump flag on /tmp and /var, so my snapshot 
> is empty for those.

There are several things in /var that are worth keeping, and they are 
pretty small.

> I don't think there's any reason to preserve /tmp, but is there any 
> good way to copy /var from the running system on the SSD to another 
> filesystem (and still preserve everything, including flags)?  My 
> impression is both mksnap_ffs and dump should only be used on a 
> complete filesystem, not a subtree.
>
> Or do I need to unset the nodump flag on /var, make a snapshot of /, 
> take a dump :-), and then split the /var out upon restore?

Snapshots don't have to be made separately, dump's -L option does that 
automatically:
http://www.wonkity.com/~wblock/docs/html/backup.html

Restoring from a dumpfile is an easy way.  net/rsync has a config option 
to support flags, but I haven't tried it.

> And would it be wise to repartition the SSD to put /var and /tmp on 
> their own partitions?

When I did that recently, I put /var on a small separate partition but 
used tmpfs(5) for /tmp.