SUMMARY: ufsdump

From: Sam Don (don_sam@hotmail.com)
Date: Thu Jun 01 2000 - 18:06:22 CDT


Hi all,

Many thanks to the following for their help:

Buddy Lumpkin
Connolly, Michael
Salehi, Michael E
Russ Poffenberger
Marina Daniels
Jay Lessert

My questions are marked with '>'. I've combined everyone's answers below.

>If a level 0 dump spans say 4 tapes, and the first tape says that it is a
>dump of /export, does it mean the other 3 tapes are all only > the /export
>filesystem,

Since ufsdump does not span filesystems, all 4 tapes are from /export.

ufsdump works on volume boundaries. So if /home contains another mount
point, say /home/foo then the /home/foo folder will be empty when you
restore /home, you then need to cd to /home/foo and restore the dump for
that particular volume.

>or could they also be of other file systems mounted under /export, or
>entirely different filesystems?

No. The "fs" in ufsdump means file system, it backs up one entire file
system and only that file system. ufs (standard ufsdump doesn't follow
symlinks or dump nfs mounts).

>When I do an ls within 'ufsrestore -ivf ..' is it safe to assume that the
>ls result is the 'index' of what is on the rest of the tapes of this
>multi-level dump?

Yes, provided that there was only one dump. When you do the 'ufsrestore ivf'
it just shows you the index of what is in that particular ufsdump. For any
additional dumps on the tapes (possibly only the fourth one in this
particular case), you will need to fast forward and look at the index again
(see below).

To get to the next dump (if any), do "mt -f /dev/rmt/?? fsf 1"
substituting your tape drive name. The /export one might take up the whole
first tape, and go onto the second one, so if you put in the second tape,
and you can't do a 'ufsrestore', just do that 'fsf' command first.

>If so, if I don't see the file I need on this first tape,
>can I skip the rest?

For a dump spanning multiple volumes, where nothing else is dumped to the
same set of tapes, the answer is yes.

However, you could a dump of /export on tape 1 but not use the whole
tape. At the end of that dump you could start a second dump which may finish
tape 1 and then "span" over to part of tape 2. That dump could finish and
not use all of tape 2 so that you could start a third dump that would finish
tape 2 and then "span" over to tape three. Get the point? If you really
don't know what is on the tape or how many dumps there are per tape then you
could use mt to skip through each dump OR use ufsrestore -ivf <tape-dev>/0n
( the n for no-rewind - don't know your tape device) to see the index and
fast forward through the dump to the next index.

The point is that just because the first index says /export there could be
many more dumps on the tape. Also, if it says it is a level 0 dump of
/export then you are getting ALL of the files/dirs under /export that are.

>About level 8 dump - how do I restore level 8s?

Same as you'd restore anything else... If you want a complete restore to the
contents of the level 8 dump, do a restore of the preceeding lower-numbered
levels, then end with the level 8. If you just want individual files from
the level 8, just restore them without restoring the preceeding dumps.

Level 0 is a full dump, everything on the file system. In normal
operations, the level 8's would be incremental dumps, and would
contain anything changed since the last level 0, 1, 2, 3, 4, 5,
6 or 7 dump. Just since the last level 0 in your case. One normal
way to do things would be to do a level 0 dump once/week, and then do
level 8 dumps the other days. So if you had this:

Date Level
---- -----
Sun 05/03/98 0
Mon 05/04/98 8
Tue 05/05/98 8
Wed 05/06/98 8
Thu 05/07/98 8
Fri 05/08/98 8

Sun 05/10/98 0
Mon 05/11/98 8
Tue 05/12/98 8
Wed 05/13/98 8
Thu 05/14/98 8
Fri 05/15/98 8

And you wanted the best possible restore that showed the way /export
looked on Wed, May 13 1998, You would restore the 5/10/98 level 0,
then restore the Wed, 5/13/98 level 8 over the top of it.

Be aware that the incremental dumps only catch files added or modified, and
do not know about files removed. Also be aware that this is just *one* way
the dumps could have been done.

This assumes you are referring to a dump per tape. It is possible to have
several dumps on a single tape. In that case, you simply jump to the next
instance, like this:

ufsrestore rvfs /dev/rmt/0 2

which restores the second dump instance from the tape.

Since I've basically combined everyone's answers, hope the above makes
sense.

Regards,
SD
________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com



This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:14:08 CDT