To INIT or NOINIT

[equus2]

Hi,

I'm still trying to understnad the difference between a backup with INIT vs. NOINIT.

I know the BOL says that NOINIT appends, and INIT overwrites backup sets, but I'm trying to understand why you would want one or the other??

That is, what is the advantage of appending vs. not appending?

Thanks!!!

 

[ptheriault]

It all depends on your backup stategy. Here is mine.
I do a daily full db backup at 12 AM to one file.
Then at 1 AM I init my log backup file
Then at 1:30 AM I start incremental log backups that append log backups to my log backup file. (NOINIT)

So I init my log backup file once a day then append until my next full backup. At that point those log won't be used for a restore so I init my file and start over. I should also mention that before I init my file everything is written to tape.

So if I have to recover my db I restore the full db backup then roll forward with my log backup file to the point of failure.

If you don't init your backup file at some point it will become very confusing on which file to restore. Backup must be restore sequentialy.

Also if you have a very large db it may not have the room to keep more than one backup set in your file.

Does that int vs noinit make sense now?


- Paul
- If at first you don't succeed, find out if the loser gets anything.

 

[olahallengren]

Another backup strategy could be to create unique file names (with date and time) for each backup. This could be done with the Maintenance Plans or with T-SQL scripts. I have a stored procedure that you could use that supports this backup strategy.

http://blog.ola.hallengren.com/blog/_archives/2008/1/1/3440068.html

Ola Hallengren

http://ola.hallengren.com