ADSM-L

Re: Monthly full backups with MODE=ABSOLUTE

2005-09-02 22:03:15
Subject: Re: Monthly full backups with MODE=ABSOLUTE
From: William Boyer <bjdboyer AT COMCAST DOT NET>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Fri, 2 Sep 2005 22:03:03 -0400
> Do you find it matters wether the data is compressed in the client or on the
> drive?   I don't know if the LTO-1 drives compress on the fly; My 3592s with a
> raw capacity of 300GB can take over 2TB of database backups.  Of course, this 
> doesn't help transfer time for e.g. copies.

Even though I see 8:1 on a tape, TSM still has to process the full uncompressed 
amount. And with LTO-1 if I don't have to process
80% of that data...first BA STG disk->copypool and then to migrate it to 
tape...that saves me a lot of processing time. My
rule-of-thumb for LTO-1 is 1GB/min on the average. If I get them to compress a 
100GB database file down to 20GB, that's saving me
160 minutes of having to process that data.

They DBA's have done some tests backing up compressed and uncompressed and have 
found that the run times are just about the same.
They are doing some testing of the restore times this weekend. If that again is 
about the same, they will turn on compression for
the filesystems that contain the Oracle DBF files. One of the beefiest ones 
does almost 200GB each time it backs up. Thankfully they
only do the full cold backups a coupel times a week. If I had to take that data 
every night....

They right now have 1,331GB disk pool, and there's normally a migration that 
happens during the backup window, too. Some days I have
to cancel the BA STG->Copypool just so I can have time to migrate before the 
night's backup window starts.


Bill Boyer
"Some days you're the bug, some days you're the windshield" - ??

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Allen S. Rout
Sent: Friday, September 02, 2005 9:22 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Monthly full backups with MODE=ABSOLUTE

==> On Fri, 2 Sep 2005 19:15:08 -0400, William Boyer <bjdboyer AT COMCAST DOT 
NET> said:

> Each node has a nodename assigned for the monthly backup <nodename>_M,
> and that's in it's own domain LONGTERM. The policy is VERE/VERD=NOLIM
> RETE/RETO=2570 and it goes to it's own disk/tape pools, separate from
> the daily backups. Right now there are 179 nodes registered in that
> domain. Not all of them are active right now, and I did manage to get
> them to at least run the test/dev/prod on different schedules. So
> they're not all trying to hit the system at the same day.

Delightful, it appears you've won a bunch of battles there.

> The daily backup of this system in 1.5TB and more. Lots of Oracle
> backups. I'm trying to get them to buy off on using compression for
> the *.DBF files. They do it for test/dev and I see as high as 84%
> client side compression.

Do you find it matters wether the data is compressed in the client or on the
drive?   I don't know if the LTO-1 drives compress on the fly; My 3592s with a
raw capacity of 300GB can take over 2TB of database backups.  Of course, this 
doesn't help transfer time for e.g. copies.


> The tape is LTO-1. They have a 3584 with 4 drives and a 3583 with 4
> drives, but right now (excluding the monthly tapes) they have over 150
> tape volumes that don't fit in the 2 libraries. I also have them
> looking for an expansion frame on the used market for the 3584. Next
> year they have budgeted to upgrade tape to LTO-3 fibre attached.

And you need more tape heads. But you know that. :)


> We are also talking about taking the monthly nodes/data to their own
> server instance. Right now the server has 3 instances: One is the
> library manager instance, then there's this production instance and
> there is another created that is supposed to be the monthly instance.
> It just hasn't been implemented.

Heh, I was going to suggest this, but thought I might sound like a broken 
record. :)



- Allen S. Rout