Best Back up strategy

[Jason_Allen_2]

We are using 10.0 for windows servers and have been doing a full back up everyday. We are getting to the point where it is not time efficient to do this.

I want to switch to where I can back up only files that have changed or been created nightly (M-Th) and a full back up each Friday.

Can I do this with one back up job or does it need to be split into two jobs?

Also, what is the difference betwenn incremental and differential? (I read the admin guide and was a bit confused, especially between modified time and archive bit on both)

Is there a better strategy for this?Message was edited by:
Jason Allen

[Shyam_Sundar]

Hello,

In this case, you can perform Differential backups from Monday to Thursday and a Full backup every Friday. You have to configure 2 different jobs, one for differential and one for Full and schedule them so that they run at the required days.

Actually when an incremental backup is performed the archive bit of every file is reset leaving behind the information to Backup Exec that those files are backed up. So that the next time only when a file is modified, the file are backed up, otherwise it is not. This happens because when a file is modified, the archive bit is set again leaving Backup Exec to back it up during the next backup job.

This does not happen with a differential Backup. A differential backup does not reset the archive bit thereby leaving the file to be backed up irrespective of the fact whether the file is modified or not after the last full backup job. This works in the following fashion.

Say you take a Full backup on Monday. Then on Tuesday you take a differential backup. On wednesday when you take a differential backup again, all the files which are modified after Monday's Full backup (before Tuesday's backup), will be backed up again inspite a differential backup was run on Tuesday.

Again only Full and incremental backups reset archive bits. Differential backups don't.

Please write to us incase of further queries on this.

Additional Information :
For information on the recent VERITAS Backup Exec security vulnerabilities, including links to the downloads for the necessary hotfixes, please refer to the following document:
Patch summary for Security Advisories VX05-001, VX05-002, VX05-003, VX05-005, VX05-006, VX05-007

http://seer.support.veritas.com/docs/277429.htm



Note : If we do not receive your reply within two business days, this post would be marked ‘assumed answered’ and would be moved to ‘answered questions’ pool.


Thanks.

So

[Jason_Allen]

Ok, that gives me two more quick questions.

On the differential back up, I want to do the archive bit option and not the modified time option, correct?

Also, does that mean that my Friday full back up will be a full back up and that my Monday differential back up will be a full back up each week too? Or does the Monday differential back up recognize that there was a full back up done on Friday and only backs up files modified or created since Friday?

[Shyam_Sundar]

Hello,

On the differential Backup, you can either perform a archive bit option or a modified time option. In either case, the files modified since last full backup will be backed up. But the strategies followed are different. You can use either of them.

And with reference to your question, if a full backup is run on Friday and a differential backup is run on Monday, then the Monday's backup job will backup only the files modified since the Friday's full backup. Remember, a differential backup run on the next day (Tuesday) will also backup all the files modified since Friday's Full Backup even though a differential backup is run on Monday.

Please write to us incase of further queries.


Additional Information :
For information on the recent VERITAS Backup Exec security vulnerabilities, including links to the downloads for the necessary hotfixes, please refer to the following document:
Patch summary for Security Advisories VX05-001, VX05-002, VX05-003, VX05-005, VX05-006, VX05-007

http://seer.support.veritas.com/docs/277429.htm



Note : If we do not receive your reply within two business days, this post would be marked ‘assumed answered’ and would be moved to ‘answered questions’ pool.


Thanks.