[Networker] Effect on incremental if clone remains but original removed?

Hi,

Please excuse the long winded question, but I want to be clear on whatI'm asking.

Question here about whether or not a clone save set that remains in themedia database will affect a subsequent incremental backup if theoriginal counterpart save set is removed?

My understanding is that NW uses the last valid media database entry forthe given save set to determine the timestamp to base the nextincremental for that same save set, assuming, of course, that thedatabase entry for the previous one is valid (e.g. not aborted). Theindexes are not used to determine what to back up, only for recoverywhen doing browsable recovers. Moreover, indexing is turned off on clonepools. But I'm unclear on how clone entries affect subsequentincrementals in cases where the original counterpart has been removed.

Let's suppose you run an incremental (incremental 1) to an indexed pool(pool=A), cloning is enabled (clone pool=A_clone). The next day, you runa second incremental (incremental 2) but this time to a non-indexed pool(pool=B). You then clone that second incremental, but to a differentclone pool (clone pool=B_clone). You then remove the media database andindex entries for that second incremental as:


nsrmm -d -S ssid/cloneid_from_original

but you keep the clone entry (from clone pool B_clone); it stays in themedia database.

On the third day, you run a third incremental (incremental 3) but thistime back to the original pool (pool=A). That's automatically cloned(clone pool=A_clone). If that's successful you then remove the cloneentry from the second incremental (incremental 2).

QUESTION: Will NW base the third incremental on what's changed sinceincremental 1? I would think that it wouldn't have any choice given thatyou removed the media database entry from the second incremental, right?In other words, the third incremental should back up exactly what itwould have done if you had never taken that second incremental, butthere is a concern here as noted below.

CONCERN: The problem here, though, is that in this case you've notremoved the clone entry (clone pool=B_clone) from that secondincremental before taking the third, so will NW still see that ssid(clone) entry and base the third incremental on the timestamp for thatremaining clone entry (clone pool=B_clone), or will it instead base iton the first incremental since the original for the second incrementalwas removed, never mind the fact that its clone entry still exists?

BTW: This question comes up because we want to run a test to see howmuch faster a given save set can be backed up with indexing turned off,but we don't want to actually turn it off on that pool since we have alot of other clients/save sets that write their data to that same poolwherein we do desire index entries. So our plan is to create a test poolwith indexing turned off, and a corresponding test clone pool, and thenswitch the affected client' s NSR resource group to use the test poolinstead, then run an incremental, analyze the results/speed, remove thatincremental save set entry and then switch the resource back to usingthe original pool, continuing (we hope) where we previously left offbefore we ran the test.

Clearly, this would work if we either didn't make a test clone or weremoved both the test clone entry and its original counterpart beforetaking the third incremental, but will it still work if we make thatclone and we don't first remove it before the third incremental is run?The reason for keeping the clone copy from the second (test) incrementalis just to have something to fall back to in case the third (normal)incremental failed, and we needed to recover something before we couldget another good back up. The test pools could then be recycled.


Thanks.

George

--
George Sinclair
Voice: (301) 713-3284 x210
- The preceding message is personal and does not reflect any official or 
unofficial position of the United States Department of Commerce -
- Any opinions expressed in this message are NOT those of the US Govt. -