Back-up Question

[Anne-Marie]

Hi

Please could someone confirm something for me.

Progress - 10.01c on a Unix platform.

The back-ups that are being performed are the overnight OS backups, the PROBKUP utility is not being used. I have found that once a week a full back-up is performed and for the rest of the week an incremental back-up. However from the Database Admin Course book it says that one of the drawbacks of using an OS backup is that you "Can't do Incremental back-ups". I questioned this with the back-up team here and they have asssured me that any file that is changed overnight is being backed up.

However I am now unsure which is right, I am more inclined to believe the Progress information and am urging them to do a full back-up every night, especially as it only takes 2 hours. Can anyone confirm or not if incremental back-ups using an OS back-up work or not, so if needed I can use this weight to urge the change to be applied as soon as possible.

Thanks
Anne-Marie

 

[RealHeavyDude]

Hello Anne Marie,

I hope, that you shut down your database before the OS backup is started and bring your database back up again not before the OS backup on the directories where database files reside is finished.

OS backup is a NO-GO for running databases. There is one exception and one exception only: One could set quiet points but personally I don't like 'em much. Every OS backup that is taken from a running database does not have any value.

Why is that:
All files which belong to the database have a time stamp (last update) which must match for all files, otherwise the database is corrupt and the only was to recover is a restore from backup. Every OS backup, even if it were lightning fast, will backup files in a sequential order and thats the reason why your backed up database files will have different time stamps in your backup and you won't be able to restore them successfully.

There is no incremental backup of a Progress database, because all files which belong to the database must change simultaneously (time stamp). So even if you do an incremental OS backup - all files must be backed up completely to ensure that you are abel to restore them successfully. There is no way you could mix and match database files from different OS backups.

That's why the probkup is the only way to get incremental backups from the database no matter what any of other guys tell you.

Personally, if I would be responsible for the disaster recovery, since nobody from the other guys ( system admins, network guys or the ones responsable for SANs ) has the dba knowledge, I would not allow them to dictate anything in the disaster recovery strategy.

For these guys a database is just another bunch of plain files like any other which they must take care of. They don't understand the concept of a database of which parts are loaded into memory. Only the database itself is able to do the syncing between memory and the files on disc.

HTH, RealHeavyDude.

 

[TomBascom]

Ask them to please restore the database with an "as of" date of last Wednesday. Try to start it.

Good luck.

When the dust settles start using probkup. You could, for instance, probkup to disk and let them pickup those files in their otherwise bogus backup process.

And then implement after imaging so that you can restore the database as of Wednesday at 3:30pm.

Plain old backups are necessary but they are not sufficient. With plain old backups your minimum exposure to data loss is the period between backups (sounds like 24 hours if your current strategy works which I seriously doubt). If your backup media fails it is even longer. Can the business really survive the loss of 24 hours of data? Do they honestly think that they can re-key it all? (Do you have any EDI or other 3rd party interfaces?) After imaging enables you to "play back" transactions against a backup and recover the missing period. http://dbappraise.com/ppt/ai.pptxIt isn't very hard to setup.