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Differential-B2D backups issues

Jeromy
Level 3
 Version 11d.

I'm having a problem with some overwrite period or something when I'm backing up to disk. The previous week's differential backups are being overwritten. For exampled. I perform a diff. backup to disk on Monday-Thurs on Weekl, A full backup to disk gets performed on Friday of Week1. A new set of .BKF files are created Monday-Thurs on Week2 for the diff. and full backups.

I wish for the diff and full backup to disk files that occur on Week1 to get overwritten by the diff and full backups that occur on Week2 to conserve disk space.

Here is my config......

A. Setup a Differential and Weekly B2D folder, with 100GB for B2D files, max side for B2D is disabled and max number of backup sets per B2D file is set to 1.

B. Setup Differential and Weekly Media Set, Overwrite protection period to 1 days and Appendable period to 5 days.

C. Setup a policy to perform 2 jobs, Job 1= a B2D backup using the Differential B2D folder and Media Set. I have the job set to Overwrite media. Job 2= is the same as above, except I've set it to use the Weekly B2D folder and Medial Set.


Any suggestions? Am I doing something wrong?

Jeromy
1 ACCEPTED SOLUTION

Accepted Solutions

shirmal
Level 5
Hi Jeromy,

You should have 2 media sets, rather than (or as well as) 2 B2D folders.
One media set is for your diffs, the other is for your weekly fulls.
For your weekly fulls, you want an Overwrite Protection Period of 7-13 days (i.e. don't overwrite a full backup for that time, during which another full should take place).
For your daily diffs, an OPP of 6 or 7 days should do (i.e. you want to keep the diffs around until a new full has been done)
 
The changes above also take into account that you should have 2 fulls lying around. If you have one full backup, and you start overwriting it and something goes wrong, then you are without a full backup. By having two fulls, if something goes wrong then you still have the previous full, and the differentials will continue to make the backup set up-to-date.
 
Also, if you are backing up to disk, you may as well do incrementals rather than differentials. It'll save disk space, and your restores will be hardly any slower.
 
See http://www.backupexecfaq.com/faq/concepts/understanding-media-sets.html to get an idea of how media sets, append and overwrite protection periods work.
 
Hope this helps
 
---cheers
 
shirmal

View solution in original post

2 REPLIES 2

shirmal
Level 5
Hi Jeromy,

You should have 2 media sets, rather than (or as well as) 2 B2D folders.
One media set is for your diffs, the other is for your weekly fulls.
For your weekly fulls, you want an Overwrite Protection Period of 7-13 days (i.e. don't overwrite a full backup for that time, during which another full should take place).
For your daily diffs, an OPP of 6 or 7 days should do (i.e. you want to keep the diffs around until a new full has been done)
 
The changes above also take into account that you should have 2 fulls lying around. If you have one full backup, and you start overwriting it and something goes wrong, then you are without a full backup. By having two fulls, if something goes wrong then you still have the previous full, and the differentials will continue to make the backup set up-to-date.
 
Also, if you are backing up to disk, you may as well do incrementals rather than differentials. It'll save disk space, and your restores will be hardly any slower.
 
See http://www.backupexecfaq.com/faq/concepts/understanding-media-sets.html to get an idea of how media sets, append and overwrite protection periods work.
 
Hope this helps
 
---cheers
 
shirmal

Jeromy
Level 3
Thanks shirmal for the info. I was able to resolve with your suggested info and plain old testing.
 
Jeromy