backing up database to one tape?

[kongfranon]

So my tsm db has been backing up properly every day, but what I notice is it grabs a new tape from scratch each day. My database is only 30 GB, I hate to waste a whole tape for just that?

Is it possible to tell it to just append to the current tape?

I am going to run out of scratch volumes very fast.

Thanks

 

[moon-buddy]

Nope - not possible.

The logic is that 'you don't put all your eggs in one basket and break them all when you stumble'.

Separating DB bcakups insures that you can recover your system even if you loose one or two tapes.

 

[kongfranon]

Thanks for the info, I need to figure out what to do right now I have it set to retain the db backup for 14 days, thinking we can restore up until 2 weeks back. I assume after that the db backups will then be able to use those tapes again? or reclaim it somehow?

I am going to see if we can purchase more tapes.

 

[moon-buddy]

Thanks for the info, I need to figure out what to do right now I have it set to retain the db backup for 14 days, thinking we can restore up until 2 weeks back. I assume after that the db backups will then be able to use those tapes again? or reclaim it somehow?

I am going to see if we can purchase more tapes.

The question to answer is - why 14 days?

In most cases, beyond 3 days maybe considered stale data already.

Yes, after the DB expiry period, the tape goes back as scratch.

 

[kongfranon]

The question to answer is - why 14 days?

In most cases, beyond 3 days maybe considered stale data already.

Yes, after the DB expiry period, the tape goes back as scratch.

It is possible I am misunderstanding how it works so let me explain and maybe I can change it:


This is what I have currently:




DB Backup Series Expiration Days: 14 Day(s)
Recovery Plan File Expiration Days: 30 Day(s)
Check Label?: Yes
Process FILE Device Type?: No
Command File Name:




The reason I was thinking of dong 14 days is because, we currently only send tapes from our DR media pool offsite one day a week on a Wed. I run the backup to the offsite pool every day, but it is too expensive for us to have a courier get the tapes and send it every day.

So if I only do 3 days, if say a disaster happens and need to recover the the entire system I can only go back 3 days is that correct? What if I need to go back 7 days from the last pickup or maybe two weeks? I would need to restore the system from two wed ago? I would need to get it at least 14 days?

Is my thinking correct?

 

[moon-buddy]

If you recall from the TSM class, the best practices is to send DR tapes offsite daily.

The DR plan is useless if kept more than what you retain the DB for. Thus, if you keep 14 days for the DB, the DR plan should be also 14 days. The plan is useless if you don't have any DB to restore.

As for the DB expiry days talk this over with your bosses. Picture the scenarios - how far back do you need to recover? How recent would you need data to be restored? What is the requirement from a legal perspective? SOX issues?

Then decide how far you need to 'preserve' TSM DB.

 

[kongfranon]

Yeah I spoke with them about this and they said it just way too much money to send offsite everyday, I was surprised they only do it once a week, but from what I understand from a SLA we are allowed to restore and lose data for 7 days. It is the requirement they have.

I guess in theory in that case I only need to go back 7 days, and should change the DR plan to 7 days as well.


Or maybe I should just do a DB backup the day before we send the tapes offsite and only do it once a week? since what is the purpose of doing a daily db backup if i will not be sending tapes offsite daily?

 

[moon-buddy]

Or maybe I should just do a DB backup the day before we send the tapes offsite and only do it once a week? since what is the purpose of doing a daily db backup if i will not be sending tapes offsite daily?

This dangerous thinking. If they could accept data lost as far as 7 days, then your setting of 14 days will be adequate.

Keep this for now and you can sleep soundly at nights.

I just hope 'the big' hit would not come your way, and your bosses realizes that they have not sent the tapes offsite that often enough.