ADSM-L

Re: AFS or DFS anyone?

1999-03-18 10:57:26
Subject: Re: AFS or DFS anyone?
From: "Prather, Wanda" <PrathW1 AT CENTRAL.SSD.JHUAPL DOT EDU>
Date: Thu, 18 Mar 1999 10:57:26 -0500
We are in about the same situation.

Yes, we use ADSM together with DCE/DFS.
But it is such a hopeless mess, we have been unable to get ADSM with DFS
working well enough to allow archiving, so we don't yet have the problem you
describe.

We too are unable to get the file-level DFS backups working properly.  We
have reported the problem to IBM, but they refuse to address the CLIENT
problem with DFS because we are still running the version 2 SERVER!

I don't think IBM has much interest in getting it to work well.  The
documentation is lousy, and the design appears to me to be very much a
patch/kludge, because as Reinhard noted, you have to maintain a zillion
virtual mount points manually to support your users properly, and there is
no good way to do it. IBM doesn't seem to have much grasp on how people
really use DFS in real-world environments that support lots of users.

So we run the BUTA interface, not by choice, but because that is what works.
SO users have no access to ADSM for file-level backup and restore, we have
do to it for them.  So they have no access to archiving, so they don't have
the problem you describe.

So far, all our DFS systems are AIX-only.  Management wants to implement
some non-AIX DFS systems next year, and I think the issues will become more
visible then.

As far as looking for a better product, fine.  But, I think the entire
problem is that the DCE/DFS community is just too small.  It just hasn't
caught on.  We have had problems installing 3rd party application
development software in our AIX DCE/DFS systems because the vendors are
UNAWARE of the existence of DFS, and the software won't run in a DFS
environment!

I don't see the problems getting better until there is some requirement out
there that makes a LOT more installations run DFS, so that vendors put more
committment there.

Wanda Prather
The Johns Hopkins University Applied Physics Laboratory


> -----Original Message-----
> From: Reinhard Mersch [SMTP:mersch AT UNI-MUENSTER DOT DE]
> Sent: Thursday, March 18, 1999 8:28 AM
> To:   ADSM-L AT VM.MARIST DOT EDU
> Subject:      Re: AFS or DFS anyone?
>
> yes, we are using ADSM together with DCE/DFS. I think, what you describe
> is a problem, but for us it is not the most serious one, because we mainly
> use AIX (and are still on ADSM Vers. 2 in that area; this should change
> soon).
>
> More serious for us is the following: We have about 44000 filesets (each
> user has one), which are organized in groups according to the user's
> initial letter. So my fileset is mounted at:
> /.../dce.uni-muenster.de/fs/u/m/mersch
>
> Of course, we do not want to maintain 44000 VIRTUALMOUNTPOINT definitions,
> so we define them on the next higher level:
>    VIRTUALM           /.../dce.uni-muenster.de/fs/u/a
>    VIRTUALM           /.../dce.uni-muenster.de/fs/u/b
>    VIRTUALM           /.../dce.uni-muenster.de/fs/u/c
>    ...
>    VIRTUALM           /.../dce.uni-muenster.de/fs/u/z
>
> We thus have to make ADSM cross mount points (option "DFSBackupmntpnt No"
> when using the DFS enabled client; the non DFS enabled client does this
> anyway, as far as I know). This is quite dangerous, because if any user
> mounts any part of the DFS file tree in his/her own fileset, we back that
> up. And there is no way to prohibit the use of "fts crmount".
>
> We are thus forced to go to "buta". I do not like that very much, because
> I consider "dsm[c]dfs" being superior: it needs less resources due to its
> incremental-forever-concept and offers better service to the users
> (individual restore of several generations of a file).
>
> By the way: since I visit the CeBIT tomorrow, any idea where to look for
> a backup/archive product doing a better job in the AFS/DFS area?
>
> Best regards,
>
> Reinhard
>
> Helmut Richter writes:
>  > Some days ago I posted here a problem which I think must startle all
> AFS
>  > or DFS sites that use ADSM. I got one (!) reply of one large site who,
>  > just like us, now feel forced to contemplate switching to another
>  > backup/archive system. All others remained silent. Is it indeed so that
>  > AFS or DFS is used only by a few weirdos like us?
>  >
>  > If you have AFS or DCE/DFS installed, please respond (to the list or to
> my
>  > email address) so that I can get a picture of whether a DCR for future
>  > basic support (simlpe files archive and backup, *not* access control
> lists
>  > or other AFS/DFS specific features) would have a chance.
>  >
>  > Please indicate shortly if you see a problem with what is described in
>  > http://www.lrz-muenchen.de/ALESia/papers/afsbug.html .
>  > If not, why not (e.g. exclusively AIX, no archival/retrieval, still on
>  > version 2, users accept arbitrary detours to get their data, just don't
>  > care)?
>  >
>  > Best regards,
>  >
>  > Helmut Richter
>  >
>  > ==============================================================
>  > Dr. Helmut Richter                       Leibniz-Rechenzentrum
>  > Tel:   +49-89-289-28785                  Barer Str. 21
>  > Fax:   +49-89-2809460                    D-80333 Muenchen
>  > Email: Helmut.Richter AT lrz-muenchen DOT de    Germany
>  > ==============================================================
>  >
> --
> Reinhard Mersch                        Westfaelische Wilhelms-Universitaet
> Zentrum fuer Informationsverarbeitung - ehemals Universitaetsrechenzentrum
> Roentgenstrasse 9-13, D-48149 Muenster, Germany      Tel: +49(251)83-31583
> E-Mail: mersch AT uni-muenster DOT de                       Fax: 
> +49(251)83-31653
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