I am trying to setup Symantec Backup Exec 12.5 to do a weekly full backup to an external USB drive. I would like to keep the last two weeks of full backups for the following reason:
Example: If I happen to have a physical disk failure while my weekly full backup is running I could loose everything because I don't have a single complete backup. That is why I also want to keep the previous week's full backup.
I have read An explanation of the "Overwrite Protection Period" and the "Append Period" and I have not been able to figure out how to set the proper overwrite protection period for this type of backup.
My understanding is that the OPP applies to the entire Media set and not just a particular backup job that is on the media. Every time a backup job is appended to a Media the OPP gets extended.
Lets say I setup a media set with a 13 day OPP and then setup a weekly full backup with append otherwise overwrite.
- 1st week backup completes
- 2nd week backup appends to media and completes
- 3rd week backup fails because disk is full and the media set still has another 7 days left on the OPP.
Am I misunderstanding how OPP works on media sets? Is what I am trying to do even possible with a single media set?
Or do I have to do this with two different backup jobs and media sets?
For example using a schedule like this:
- 1st Sunday backup to Media1
- 2nd Sunday backup to Media2
- 3rd Sunday backup to Media1
- …
Best Answer
You're understanding OPP correctly. The OPP period is calculated from the date of the last write operation to the media.
If the USB is large enough for 2 weeks of backups before it becomes full then simply use two USB drives: One drive for weeks 1 and 2 and another drive for weeks 3 and 4. Then set your OPP to 14 days.
If your first full backup starts on the 1st (week 1) and the last write to Media1 is on the 14th (week 2) then the OPP would extend to the 28th. You then begin week 3 with Media2 on the 15th going through the 28th. When the cycle begins again on the 29th Media1 is overwriteable again.