ADSM-L

Re: Large ADSM installations

1997-04-15 14:08:33
Subject: Re: Large ADSM installations
From: "Prather, Wanda" <PrathW1 AT CENTRAL.SSD.JHUAPL DOT EDU>
Date: Tue, 15 Apr 1997 14:08:33 -0400
Something to consider -

I find most user files follow the 90-10 rule, or maybe 95-5:  there are
a small number of files that change all the time, but most files change
very infrequently.  I found the number of versions of files we retain
has less effect on our tape pools than the time we retain them.

If you allow the clients to have 8 backup versions, their oldest
available backup of something like the NT registry, which changes every
day, will be only 8 days old.

But the oldest available backup of a file that changes only once a
quarter, will be two years old.

I have found in past lives as a storage manager, that it's the old files
that take up space on your server- the length of time we retain extra
backup versions has more impact overall than the number of versions we
keep.  We tell our users that they can have 6 backup versions, but we
discard all inactive backups that are over 60 days old.

Your environment may of course be different, and this does not apply to
the case where the "frequently changing file" is a large data base.

>----------
>From:  Mike Wilson[SMTP:mwilson6 AT TUELECTRIC DOT COM]
>Sent:  Friday, April 11, 1997 5:25 PM
>To:    ADSM-L AT VM.MARIST DOT EDU
>Subject:       Re: Large ADSM installations
>
>Our database had grown to 15gb until about a month ago when we split ADSM
>into 2 separate servers. We also cut back on the number of  backup versions
>from 8 to 5 and started cleaning up some other misc. garbage in the
>database. We are still in the process of exporting nodes from the old server
>and importing to the new one for balancing the workload. Right now one data
>base is 9gb & the other is 4 gigabytes. We are MVS 5.2.2 and ADSM 2.1.0.10.
>
>At 11:34 AM 4/11/97 -0700, you wrote:
>>I'm curious to hear from others that have large ADSM
>>installations (multi-GB ADSM databases). I'm getting a little
>>concerned at the rate at which our database is growing. It is
>>currently ~14GB, and it has grown by 5GB in just under two
>>months. We have had a lot of activity, and we are in the
>>unfortunate position of storing a great many very small files--it
>>seems such a shame to spend 1K of database space for a 40 byte
>>file, especially when we've got thousands of 40 byte files.
>>
>>I wonder if anybody else with a large installation might share
>>there experiences/configurations.
>>
>> -- Tom
>>
>>"If I could dot the 'i' in a Michigan     Thomas A. La Porte
>> game and the good lord came to take me   Archivist, Feature Animation
>> the next day ... at least I could        DreamWorks SKG
>> die happy." - Beano Cook, ESPN           <tlaporte AT anim.dreamworks DOT 
>> com>
>>
>>
>Mike Wilson
>Storage Administration
>Texas Utilities
>
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