The number of backups you customarily keep is regulated by the
question "How far back may I have to go to restore something useful".
For example if you are backing up programs written by your staff, after 2
or 3 major changes it will be almost impossible for a programmer to say
what an older version contained, but if a new version blows up he may
need the previous copy or the one before it. Usually we keep 5 copies
and keep the latest for 1 year after it is deleted.
Commercial software like Lotus, Windows, Word, etc, we only make
one copy. They can always be restored from their CD, but a copy on
line is handy for quick fixes or total system restores. Old reports may
need to be kept longer but only one copy per version. On database files,
other than the contracted retentions, how far back can you restore and
not lose the integrity of the new data?
It basically boils down to business decisions on how useful is the
data as it ages. If it becomes completely outdated with time and
revisions keep very little of it. If you need archives for legal or
contractual purposes, make a point in time snapshot and store each
version.
>>> "Yelle, Michael 2-3823"
<MGY4V AT HSCMAIL.MCC.VIRGINIA DOT EDU> 01/13/98 09:24am >>>
Questions: What is a "reasonable and customary" number of backup
copies
to keep? How long should they be kept? We are a University Hospital
environment.
Background: We use adsm to backup a number of Novell, Widows/NT
and AIX
boxes. We currently have 900+ gigabytes of ADSM managed data in a
TAPEPOOL. It is growing at about 100 gigabytes a month. Our default
policy currently is to keep 15 copies (VEREXISTS) of each file for 18
months (RETEXTRA). We would like to reduce this value to control
growth
in the storage pool.
For some of our data we have specific business requirements to keep a
certain number of copies for a certain period of time. My question is
not concerned with this data. Rather it is directed at user data owned
by many different people on Novell Fileservers. No specific retention
business requirements have been mandated for this data.
Any help would be appreciated.
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