Clarification on Sessions

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Newbietoo
Posts: 52
Joined: Tue Apr 05, 2005 12:25 am

Clarification on Sessions

Post by Newbietoo »

Hi,

I'd just like to clarify my understanding of Sessions. For example...

Assume I execute a given Job (A) for what becomes Session 10 i.e I started with full back up and this is my 9th incremental backup; then after the Job has finished, I delete Sessions 1 to 9. If I now restore A, would my database be restored to the same state that it was prior to running Session 10? Will the backup contain ALL my data e.g. as it would have done had I performed the Job as a full backup? I appreciate there would be a physical difference, but I'm talking "logically" here of course.

Essentially, I'm seeking to understand exactly what I may safely delete, assuming that I only want to cater for disasters and be able to recover back to the state my database was in immediately before the last back up. For this exercise assume I don't need access to the prior state of any data i.e files pre-the latest changes or data that was deleted.

In a similar vein, as you've probably addressed this before, can you point me to further information on "pruning" (I have read the manual/help), but I'm still not clear. Again, following on from the above, assume I DO want to hang on to some old versions of just some files, I want to get clear exactly how do I do that?

A brief document on backup scenarios/strategies would be really handy. I really like AIS and except for a few queries, got the hang of it pretty quickly. I appreciate that backup strategies are a big topic, but I'm thinking here of making better use of the way AIS works, specifically working with incremental backups. With a few examples, Users could easily mix and match methods to suit their needs.

Thanks
Patrick
Newbietoo
Barry
Site Admin
Posts: 1529
Joined: Tue Aug 20, 2002 3:16 pm

Backup sessions: Brief explanation by example

Post by Barry »

You are correct in your assumption: AISBackup will remove files from the backup that only existed in sessions 1-9, it will retain all files that only exist in session 10. Session 10 will look and behave like a full backup.

Anybody can demonstrate the behaviour of AISBackup themselves by creating a text file under a test folder containing the text ‘aa’ and backing up just that one folder. Then change the file text to ‘bb’, create another file (file2.txt) and backup again. Then change first file again to text ‘cc’ and delete the second file then backup again.

The result will be:

Session 1: File1.txt 'aa'

Session 2: File1.txt 'bb', File2.txt

Session 3: File1.txt 'cc' (File2.txt has gone)

If you remove sessions 1 and 2 using the Manage Backup / Undo Backups (Prune Backup Sessions) option only session 3 will remain with the version of the text file containing ‘cc’. Of course you may also want to check that all the previous sessions contained the correct File1.txt.

You may have chosen to remove sessions 1 and 3, in that case only session 2 containing File1.txt (with text ‘bb’) and File2.txt will be in the backup.

We intend to add some more backup / restore scenarios to our web-site, meanwhile, have toy seen the disk to disk disaster recovery option?

http://www.aiscl.co.uk/USBDR1.htm

Barry
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