ADSM-L

Re: AFS backups - still confused

1998-09-22 13:14:38
Subject: Re: AFS backups - still confused
From: "Kent L. Johnson" <johnsk6 AT RPI DOT EDU>
Date: Tue, 22 Sep 1998 13:14:38 -0400
My summarization of the difference between the "buta" backup strategy and the
dsm.afs style of backup is the following.

1) buta

The "buta" backup style provides AFS disaster recovery.  All of the necessary
data is stored to restore AFS partitions to an AFS server, in the event of
loss of a disk or server.  It does not allow AFS users to backup and restore
AFS data, using the ADSM backup model.  All backup and restore operations
require operator intervention.  ADSM management classes do not control file
retention and expiration for the AFS files data.

2) dsm.afs

The dsm.afs backup style provides the standard ADSM user interface and
backup/restore model to AFS users.  Users can have control over the backup of
their data, and can restore individual files without requiring operator
intervention.  Individual AFS files are maintained by the ADSM system, and
the ADSM management classes control file retention and expiration.
 Additional information is needed in order to restore an AFS server disk.  I
don't know exactly how you could use the ADSM backup data to restore an AFS
partition.

We have chosen to continue backing up AFS using buta.  We considered offering
users the ability to use the dsm.afs functions to backup their data, in
addition to the buta backups but decided that we didn't want to allocate the
additional disk space for user's ADSM managed data in addition to the buta
data.  We decided that the disaster recovery protection provided by buta was
necessary in our environment.  The use of buta has freed up considerable
operator time, since ADSM handles the tape mounts.  The operator doesn't need
to continually check to see that the AFS backup operation is continuing to
write to the current tape, and mount new tapes when needed.

Kent

On Sep 22, 11:37am, Pat Wilson wrote:
> Subject: Re: AFS backups - still confused
> How do you detect mountpoint loops when they happen?  I've only
> got 3400 volumes, but the manual-suggested "define a virtual
> mountpoint for each volume" would seem to be execessive...
>
> How about disaster recovery restores?  If I'm backing up with
> dsm*afs, how do I recover, say, all the volumes on a particular
> vice partition?
>
> Thanks.
>
> Pat Wilson
> paw AT dartmouth DOT edu
>
> Steven P Roder <tkssteve AT REXX.ACSU.BUFFALO DOT EDU> writes:
> >  Hi All,
> >
> >       We backup our DFS filesets via ADSM as mountpoints on an AIX box,
as
> >  we run the Sun Server, and the Sun Client does not have DFS support.  We
> >  are doing it this way because the buta tools only backup/restore at the
> >  fileset level, and we do not want to have to restore entire filesets to
> >  alternate locations, and then grovel through that looking for one file.
> >  ADSM gives us file-level detail, as well as a single tool, as Curtis
> >  points out.  There are some caveats with using ADSM this way, like the
> >  user being able to change the ACL's such that we cannot back the file
up,
> >  and the user creating a loop in the filesystem by creating a mountpoint
> >  that points back into the tree, but we see these as more managable
> >  problems than using buta/butc.
> >
> >  Hope this helps,
> >
> >
> >  On Tue, 22 Sep 1998, Magura, Curtis wrote:
> >  > Pat,
> >  >
> >  >    We plan to use ADSM to backup our AFS cell just haven't yet. The
primar
> y
> >  > reason is to have one tool, one interface, one place to verify all
backup
> /
> >  > recovery activity. At least that's we think it's going to do for us.
Alos
> >  > gives us access to a tape library. We are using an IBM 3575. I agree
it do
> es
> >  > seem to add a layer of complexity to it though. Actually that's one of
the
> >  > reasons the AFS backup's aren't done yet. I would love to hear from
anyone
> >  > on the list that's using ADSM to backup AFS or DFS and what they have
> >  > learned.
> >  >
> >  > Why would/does anyone use the ADSM AFS backup clients (as opposed to
> >  > just using buta and the AFS backup suite)?  Seems like dsm(c)afs
> >  > just adds complexity, and you don't get backup by volumes...
> >  >
> >  > Thanks.
> >  >
> >  > Pat Wilson
> >
> >
> >  Steve (unVMix Systems Programmer/Dude) Roder
> >  (tkssteve AT ubvm.cc.buffalo DOT edu | tkssteve AT acsu.buffalo DOT edu |
(716)645-3564 ,
> >     | http://ubvm.cc.buffalo.edu/~tkssteve)
>-- End of excerpt from Pat Wilson



--
Kent Johnson                        Internet: johnsk6 AT rpi DOT edu
Kent Johnson                        Internet: johnsk6 AT rpi DOT edu
Unix Systems Programmer (VCC 323)      Phone: (518) 276-8175
Rensselaer Polytechnic Institute         Fax: (518) 276-2809
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