On Thu, 18 Mar 1999, S W Luan wrote:
> (1) When using dsmcafs, dsmcdfs, is a large number (sometimes tens of
> thousands) of VIRTUALMOUNTPOINT definitions for all the filesets/volumes
> required? How might one be able to speed up the file backup process?
>
> There is a way to do per-volume (or per-fileset in DFS terminology)
> VIRTUALMOUNTPOINT without having to define/maintain them explicitly. A
> script can be written to list all the volumes in the cell and mount them
to
> a selected directory (e.g., /afs/almaden.ibm.com/.adsm). You use the
> environment-variable support in ADSM in the dsm.sys file to define a
> generic VIRTUALMOUNTPOINT. For example,
>
> VIRTUALMOUNTPOINT ${AFSVOLUME}
.....
Point (1) of Luan's remarks are exactly what we do.
Based upon an idea, Heidelberg University Computing Centre
http://web.urz.uni-heidelberg.de/ADSM/
uses since early ADSM-days (called WDSF in these days, running an ADSM-server
on a VM-machine), our scenario is as follows:
Environment:
AFS-servers running on HP-machines under HP-UX 10.20
AFS-client-machines under HP-UX 10.20
AFS-client on a RS6K C10, 64 MB, AIX 4.2.1 ( 4.3.2 soon )
dsmcafs (V3.1.0.3) backing the whole of AFS user-$HOMEs on FILE-basis
dsmbuta for an additional volume backup
ADSM-server (V3.1.1.5) under AIX 4.2.1 ( 4.3.2 soon ) on a F40, 256 MB
Dual-Processor
Backup:
User-$HOMEs are in AFS
our directory-structure is
/afs/tu-bs.de/usr/usrxx/individual_user
the "usrxx" runs from "usr0" to "usr99", i.e. xx = UID modulo 100
( The UID being the numerical uid of a user )
We've about 15000+ VirtualMointPoints (VMPs)
The VMPs are addressed in the dsm.sys AND dsm.opt files via ${USER_DIR}
(dsm.opt : DOMAIN ${USER_DIR}, dsm.sys : VIRTULMountpoint ${USER_DIR} )
This USER_DIR env-variable is set in a script per "dsmcafs"-call, i.e.
we run each night 15000 "dsmcafs" calls, i.e. one call per user.
in this big loop we check wether the resp. afsvolume was accessed within
the last 3 days, i.e the # of actually active afsvolumes is about 10%
of the 15000 afsvolumes and ONLY these ca. 1500 are really backup'd.
currently we run 4 streams in parallel based upon our tree-structure
(0 <= xx <= 24) (25 <= xx <= 49) (50 <= xx <= 74) (95 <= xx <= 99)
on a relatively small client-machine ( IBM C10, 64MB ) lasting ca.
4 - 7 hours per stream ( depending on the weekday), so NO time-problem
with a file-backup.
How many streams You actually run very much depends on the capabilities
of the ONE ( YOU need 1 license !! ) client-server machine, i.e. a
stronger machine than e.g. our C10 could easily run more than 4 streams
in parallel.
NOW the restores:
again taking the idea of Heidelberg University + the ENV-variable-
facility in dsm.opt + dsm.sys the individual user runs a "dsmc"-script
which does an
export USER_DIR=$HOME
The ${USER_DIR} being used in the dsm.opt AND dsm.sys files
(see backup above )
additionally the "dsmcafs" is called e.g.
dsmcafs restore -server=client_machine_which_does_the_backup ...
the DOMAIN is recognised properly by "dsmc/dsmcafs" BUT NOT by the GUI
"dsm/dsmafs".
We therefore recommend the "line"-interface for real work.
The GUI presents the above mentioned 15000 VMPs, BUT if You train the
user to use the "search"-Button, the GUI presents a popup-window, where
the starting-point is $USER_DIR.
this works BOTH for HP-UX-clients (/usr/adsm/dsmc) AND AIX-AFS-clients
(/usr/lpp/adsm/bin/dsmc /usr/lpp/adsm/bin/dsmcafs )
So, if we don't bother with AFS-ACL's ANY user on HP-client machines
can do restores. If a user needs the ACL's we currently tell him to use
an AIX-box ( using the dsmcafs )
Remarks on ADSM+ARCHIVE:
we don't use ADSM's ARCHIVE yet and probably won't use it in the future,
because we feel ADSM is still not yet settled down for LONG TERM
( > 5 years ) archiving. A further point is the lack of accessing
an archived file in an emergency case ( i.e. no ADSM-DB available ).
we therefore intend to use a product from LEEDS University, UK
http://www.leeds.ac.uk/ucs/systems/archive.html
http://www.leeds.ac.uk/ucs/documentation/how/index.html
( HOW 14 How to archive files )
http://www.leeds.ac.uk/ucs/systems/archive/
http://www.leeds.ac.uk/ucs/systems/archive/sysprog.html
which we think addresses the needs for university users by far better
than ADSM does.
--
MfG / Ciao - - - - - - - - - - - - - - - - - - - - - - - - - - - -
MfG / Ciao - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Peter Dümpert Email: p.duempert AT tu-bs DOT
de
Rechenzentrum der Technischen Universität Fax : ++49/531/391-5549
D 38092 Braunschweig Tel : ++49/531/391-5535
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