ADSM-L

Re: 3570 tape drives & Maximum Client backup sessions

1998-12-10 02:24:37
Subject: Re: 3570 tape drives & Maximum Client backup sessions
From: Marc Layne <mlayne AT FGH.CO DOT ZA>
Date: Thu, 10 Dec 1998 09:24:37 +0200
Hi Matt

We are having multiple I/O errors reported regularly and this cause the
backups to fail. My client is blaming ADSM for the problems even though
it is clearly a media/hardware problem. I am attempting to ensure things
like regular cleans and also the versions of firmware vs ATAPE drivers
recommended by this wonderful group.. who knows if it works then I will
like the drives again. The concept and the operation is good when they
work... :-)

Tx for th info..

Ciao Marc

                -----Original Message-----
                From:   Matt Cleland [SMTP:mcleland AT msiinet DOT com]
                Sent:   Tuesday, December 08, 1998 6:39 PM
                To:     mlayne AT fgh.co DOT za
                Subject:        RE: Maximum Client backup sessions

                Mark..

                You've got it right..  When backing up directly to tape,
you can only get 1
                concurrent session per tape device.  If you go to disk
first, you can have
                multiple concurrent backup sessions.  My usual
recommendation is to
                configure a disk storage pool as the initial backup
location.  Size it so
                that it will easily contain a average daily incremental.
That way, all the
                backups can complete without having to compete for tape
devices.  Then,
                after backups are done, kick off migration to move the
data into the tape
                library.

                There are lots of variables that can affect this
environment, but the 1:1
                session:tapedrive limitation is hard and fast.  Only by
injecting a diskpool
                in the middle will you solve your issue.

                PS: Why don't you like the 3575-L24?  It seems to be a
great solution for
                ADSM..


--------------------------------------------------------------
                Matt Cleland
                Matt Cleland
mcleland AT msiinet DOT com
                IBM Certified Specialist - ADSM
                Midland Systems, Inc.                   (618) 345-0864
                St. Louis, MO                           (618) 346-1779
FAX


                > -----Original Message-----
                > From: ADSM: Dist Stor Manager
[mailto:ADSM-L AT VM.MARIST DOT EDU]On Behalf Of
                > Marc Layne
                > Sent: Tuesday, December 08, 1998 8:19 AM
                > To: ADSM-L AT VM.MARIST DOT EDU
                > Subject: Maximum Client backup sessions
                >
                >
                > Hi All
                >
                > I'm sure there is quite an easy answer to this but I
cannot seem
                > to find it
                > anywhere...
                > I have a client that wants to backup approx. 30
clients simultaneously to
                > an ADSM v3.1 server.They have a 3575 L24 library
(yuck) attached to the
                > server with 6 drives (two used for Informix logging)
and 4 for backups.
                >
                > They are backing up directly to tape currently. They
are not able
                > to backup
                > more than 4 clients simultaneously even though the
maxsessions
                > parameter is
                > set to 40.The first 4 clients grab the four drives and
the others are
                > unable to run. I have considered backing up to DISK
first to
                > alleviate this
                > problem. Is there something I am missing?? Can you
backup to tape more
                > clients than there are drives without backing up to
disk first?? If so
                > where can I find the information or is there a
parameter I have to change
                > .. Help Please.....
                >
                > Tx Marc
                >
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