Backup db to TSM only use one session

Uthuras

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Aug 3, 2004, 11:54:31 PM8/3/04

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Greetings,

We have DB2 V 8.1 with FP 4 on AIX 5.2. Our database backup is done
using TSM v
4.1.2. However, we notice TSM make use of only one session even though
we defined 4 sessions for backup. Here is the command

db2 "backup db $dbname online use tsm open 4 sessions with 8 buffers
buffer 3072 parallelism 6"

How do we enable the 4 sessions ? Is there any parameters need to set?

Please help!!!

Thanks

Uthuras

Ian

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Aug 4, 2004, 12:42:43 PM8/4/04

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That is the correct way. Are you sure you only have 1 session connected
to the TSM server? During the first minute or two of the backup, you
will normally see only one session, and then the others sessions will
connect and start sending data.

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Uthuras

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Aug 4, 2004, 11:45:04 PM8/4/04

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Hi Ian,

in fact, the session never get started even after hour. Another thing
that
i notice that the backup machanism using TSM seem to be very slow. I'm
not sure whether it is due TSM or my configuration on buffer size.

Sometime back i noticed a post on calculating the buffer size for
backup. I used the following to calculate the buffer size

I have about 77 table spaces. 15 table spaces use 32 Extent size and
the rest
of 62 table spaces uses 8 Extent size. The total extent for entire
database
is 976.

This is how i assign buffer size for 8 buffer

976 * 4096 = 3997696
3997696 * 8 = 31+ MB

So, i intend to modify the backup script as

db2 "backup db $dbname online use tsm open 4 sessions with 8 buffers

buffer 7808 parallelism 6"

As you can see my number of pages has been increased. I just wondering
whether
this would help me out speeding off backup process. Is there any other
method
or formula that i could use to optimize the backup process??

Please advice!!

Thanks
Uthuras

Ian <ian...@mobileaudio.com> wrote in message news:<41111202$1...@corp.newsgroups.com>...

Joachim Klassen

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Aug 5, 2004, 5:57:16 AM8/5/04

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Have you set the maximum number of mountpoints for your TSM node to
(at least)4 ? IIRC the TSM node attribute is MAXNUMMP

HTH
Joachim

uth...@hotmail.com (Uthuras) wrote in message news:<2ebe688f.04080...@posting.google.com>...

Uthuras

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Aug 5, 2004, 9:36:48 PM8/5/04

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Hi,

MAXNUMMP indeed set to 4. But why when backup running only one session
active while the reset 3 waiting idle. Is there any other setting need to
be set??

Thanks
Uthuras

JoKl...@email.com (Joachim Klassen) wrote in message news:<b5788ff3.04080...@posting.google.com>...

Dale McInnis

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Aug 9, 2004, 7:59:39 PM8/9/04

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Check the TSM target storage group to ensure that COLLOCATION is not
enabled. This will only affect tape pools the result is that only 1 tape
will by used for each TSM Node, which in your case will be the DB2 server.
I have found that using a buffer size greater than 4097 does not help
performance much, and since you are sending the data over the network to a
TSM server you are better off using a smaller buffer size and increasing the
number of buffers. Do you see the other 3 sessions being started on the TSM
Server?
TSM 4.1 is VERY old code, I would recommend you upgrade to at least TSM 5.1
Hope this helps

Dale McInnis

"Uthuras" <uth...@hotmail.com> wrote in message
news:2ebe688f.04080...@posting.google.com...

Uthuras

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Aug 9, 2004, 10:05:18 PM8/9/04

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Hi all,

Is anyone out there can help me figure out this problem? i'm not sure
what else i could check and how to go about resolving this issue

Please help!!

Thanks
Uthuras