Incremental Backups

[taqvia]

Hi,

Getting confused on how incremental bkup actually works. What i Understand is that everytime a bkup is done master block bkup counter is incremented. Now when we update a particular databse block progress will copy the Master block Bkup counter to the block bkup counter. Till here it is fine.

Now My confusion Progress states "PROBKUP backs up every database block where the counter is greater than or equal to the master block counter. " will it possible that the Database block bkup counter will become greater than master block bkup counter.

eg lets say we have Master block bkup counter value = 2, when an update is made to the database block bkup counter for block will be set to 2, now everytime the database block is modified the value will always be 2 until next bkup is taken.

It seems statement "greater than statements hold true"
holds true only when -io parameter is specified .


Please help in understanding this better.


Arshad Taqvi

 

[parul]

Hi Arshad,

I think you are getting confused about the overlap option of probkup.

PROBKUP backs up every database block where the counter is greater than or equal to the master block counter, less the overlap value you specify.

That mean if the master block has 5 and -io is 2, progress will back up all the block from
5 - 2 = 3
till 5 (current).

All the blocks where counter is equal to or greator than 3.

-Parul.