Confused on management class for TDP Exchange

[Moebius]

Hello,

I am trying to understand how the mgmt classes work with TDP for Exchange. I am only making legacy backups. I run a weekly full (on Sundays) and daily incrementals (all other days).

I seem to understand from the manual that the VEREXISTS parameter controls how many full backups will be kept in my storage, and the RETONLY parameter is in charge of the incremental backups, since each incremental has an unique name and is inactivated by any subsequente backup (full or incremental).

So, given the full and incremental serialization I'm taking, should I want to keep (say) the last 21 days worth of backup, how should I set my copygoup values to?
Would VEREXISTS=3 and RETONLY=21 be a sensible setting? And what about VERDELETED and RETEXTRA, can I just disregard these parameters in this context?

I remember I found a document on the 'net that explained this in plain words but can't seem to find it anymore.

Thanks!
Lucio

(TSMserver 5.5.3 on Win2003-x32, Exchange Server 2007 on Win 2008-x64, TDPExch 6.1.1.0)

 

[moon-buddy]

If yoy need to have only one active and 2 inactive, the version exist set to 3 is OK.

Also, if you need to keep only for 21 days the last version, then the setting of 21 suffices.

As noted, full backups is gnerally all that is need when restore Exchange UP TO THAT POINT. Otherwise, you need the subsequent incrementals.

 

[Moebius]

Thanks. The version concept is easily understood for file backups with the BA client, but it appears more obscure (to me at least) when it comes to Exchange or SQL backups, where "files" and "versions" have different meanings.

What I gather from the manuals and other information is that the object name that TSM assigns to the full backup objects is always the same, hence the subsequent full backups are new "versions" of the same; while any incremental backup object has an unique name, so there will never be more than one version of an incremental, which is immediately inactivated by any subsequent backup. This is why the RETONLY parameter controls the incrementals.

Am I getting this right?