help me setup Veritas 9.1

Backup to disk of an exchange server can get VERY large. Depending on the size of your backups a single 1TB disk might not hold 4 weeks worth.

Setup 3 disks and do your exchange to one, full to another, and differential to a third. Then see how much space is used after the first week. If you don't have enough disks do one backup per drive then empty the drive and use it over after recording the space used for that type of backup.

If you use scheduled jobs change the disks like clockwork before the next scheduled backup starts. If you can, let the rotation continue until you hit a 2nd week and can see how much space is used.

You'll probably find at some point that one or more of the disks will run out of space and Backup Exec will start overwriting your backup files from a prior week.

Once you are darn sure you have enough space to hold multiple weeks worth of data you can start playing with setting Overwrite Protection policies. You have to change the media properties to protect the backup files in that set for some number of hours, day, weeks, years, or infinitely. I would suggest setting the overwrite protection to the number of days +1 that corresponds to the number of weeks of backup -1 or -2 that you think you can hold based on the space and prior backups. For example if you think the drive will hold 4 weeks of data set the overwrite protection to 22 days or even 15 days and watch it very closely because if it runs out of space the backup job will just hang waiting for you to give it another drive.

You may eventually decide that you can do all 3 sets on one disk but for less time or that it works better to have more disks per week so each disk has more time on it.

In my case my backup to disk is non removable and I use LTO-3 tapes for off site storage. It takes me one tape for the full and a partial for the Diff per week.

Maximum number of backup sets per backup-to-disk file: 8000 (I just chose the largest)

BTW this is how many days/weeks/runs of the backup you can have sharing a single backup file on the disk or tape. This number should be set lower if you expect the drive to fill up. There is nothing wrong with the default option of 100 if you aren't hurting for space but I have mine set at 2 as I want those shared files freed up sooner for the future weeks backups.

It might also be worth mentioning that if you don't want to defrag those drives you'll want to use the "allocate the maximize size when creating the backup to disk file" or that shared file that spans 8000 backups will get fragmented even more every time your backup runs and eventually the non shared backups will get fragmented by the leftovers of the one file that keeps stranding small blocks all over the disk.

http://seer.entsupport.symantec.com/docs/272517.htm makes it look like 9.1 might not have the "allocate the maximize size when creating the backup to disk file" option. If that is the case that would be another reason to lower the number of backups that can share the file. You would also need to do something to alleviate fragmentation if the backups slow down too much.

I'm not sure, but I believe you are going to need a separate tape for each backup set. Most likely three tapes: Mon-Friday, Saturday, Sunday.

If you try to use the same tape for a different backup set, it can't append to that tape and will overwrite it.

Update: apparently you're not using tapes, but the same idea applies to whatever media set you're using.