> For backups the settings are as follows:
>
> VERSIONS DATA EXISTS = 2
> VERSIONS DATA DELETED = 1
> RETAIN EXTRA VERSIONS = 30
> RETAIN ONLY VERSION = 60
>
> ...
>
> The data being backed up the most often is from a pop-mail server which
> is very active data. The numbers currently being used from STANDARD
> settings make me wonder what other people out there are using. I know
> I can make new copygroups and domains but I was curious about what
> numbers you use for backups.
>
> In particular if you are backing up user mail files of any kind what
> settings do you use.
We use
VERSIONS DATA EXISTS = 8
VERSIONS DATA DELETED = 8
RETAIN EXTRA VERSIONS = 50
RETAIN ONLY VERSION = 100
The reason: Just imagine the following scenario (which actually occured here):
A users's mailbox is corrupted.
Then comes the weekend.
Then it takes one or two days for the user to detect the problem.
Then he/she tries to contact you, but you are temporarily not reachable.
Another day is lost.
During all this time, new mail arrives. Thus, each night a new backup
copy of the mailbox is made. So, if you want to be able to restore
a backup made before the corruption occured, you need a high number of
versions to be kept.
Of course, there is a price to be paid for it. In our case, our mail server's
/var/spool/mail containes close to 25000 mail folders occupying 2 GB;
in the ADSM server there are lying close to 100000 files occupying 10 GB,
which means a factor of 4-5. But we think, that it is worth the price.
Hope this helps.
Reinhard Mersch Westfaelische Wilhelms-Universitaet
Universitaetsrechenzentrum, Einsteinstrasse 60, 48149 Muenster, Germany
E-Mail: mersch AT uni-muenster DOT de Phone: +49(251)83-31583
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