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Oops I am sorry,Quote:
Originally posted by Kishore
I mentioned that I am taking cold backup every 15 days not every day
I meant whats the advantage of taking a cold backup every 15 days when you already are taking a Hot Backup everyday.
Does it have any edge ....
isn't a full hot backup enough so that I don't have to do cold backups anymore? most of our servers should be up 24/7. Also, if archived logs are being multiplexed into several location do I still have to backup archived logs every hour?
I know this depends on the size of the database and the storage capacity of the backup medium but can you guys recommend how long should i keep archived redo logs before I delete them? Thanks.
Your MTTR is determined by your business model. You can figure out what your recovery time is by crashing your server and recovering it. If it takes you 1 hour to pull the database off tape and 1 hour to recover, your minimum MTTR is 2 hours. If it takes 1 hour to pull the data off tape, 1 hour to pull the incrementals off tape and 1 hour to recover, you have a minimum 3 hr MTTR.Quote:
Originally posted by ronnie
How do you determine what your MTTR is and at what MTTR does a incemental backup makes sense.
You only need the archived redo log files from before the last logswitch before the last backup.Quote:
Originally posted by TheSlob
can you guys recommend how long should i keep archived redo logs before I delete them? Thanks.
In other words, say at T0 a logswitch occurs. At T1 you start your hot backup. At T2 you end your backup. You need to have the archived redo logs from T0 to current.
Again, that depends on your business model. In my environment, everything has to be up 24X7 so a cold backup would be impossible.Quote:
Originally posted by TheSlob
isn't a full hot backup enough so that I don't have to do cold backups anymore?
As Jeff said, it depends on the business model. I am taking cold backup to test the recovery every 15 days. Taking backup is not sufficient unless you test them to recover the database.
If cold backup is not possible, test them with Hotbackup. Testing backups frequently is as important as taking backups.
I couldn't agree more. This is one of the top mistakes new (and some experienced) DBAs make every day.Quote:
Originally posted by Kishore
Testing backups frequently is as important as taking backups.
can somebody give an example on how one would go about taking incremental backups. I mean the strategy you would use to backup and recover.
Any pointers to white papers,Articles or case studies would also be very helpful.
Thanks
We use RMAN to backup our database (~150 Gig) to tape every night. We use Tivoli Storage Manager with TDP so the data goes directly to tape.
We implement the following incremental stategy:
Sun Mon Tues Weds Thurs Fri Sat
0 2 2 1 2 2 1
With this a 0 means FULL, 1 means back up everything that has changed since the last "1" or lower. 2 means back up everything that has changed since the last 2 or lower.
With this we do an incremental 0 (FULL) on Sunday. On Monday, everything that has changed since Sunday. On Tuesday, everything that has changed since Monday. On Weds, we do everything that has changed since SUNDAY. On Thursday, everything that has changed since Weds... and so on.
With this scheme we never have more than 4 days worth of backups to apply. So if the DB crashed on Friday, after the backup, we would have to apply Sun, Weds, Thurs & Friday, plus any archive logs since the Friday backup.
Obviously this will take longer to restore than doing FULL backups every night, but cost of tapes and time to do backups was a determining factor for us.
In addition, we do full exports every night and backup our $ORACLE_HOME every night.
Hope that helps you with an Incremental Strategy!
Jodie
and what about windows. They have registry in windows. How do you backup and restore the oracle home in windiws 2000Quote:
Originally posted by pando
there is no registry in unix, install linux in your PC and you will see
How do you test a backup. Is it by bringing the backup database on another machine or there are some other ways...Quote:
Originally posted by marist89
I couldn't agree more. This is one of the top mistakes new (and some experienced) DBAs make every day.Quote:
Originally posted by Kishore
Testing backups frequently is as important as taking backups.
Thanks