Differential Backups
I have a dilema.
Curretly on one server we run the following backups:
1 monthly full backup - kept for a year
1 weekly full backup - kept for 6 months
1 daily differential incremental backup - kept for 6 months
and once a weekend we run another full backup to offsite which is kept for 1 month.
With our current set up, I feel that it is a waste of tape to keep doing the weekly full back up that we keep for 6 months. That weekly full can be recreated with the monthly, plus all of the incrementals from that week. However, what worries me is the weekly off site tape we only keep for 30 days. If it happens on saturday, and information changed 4 hours before it backed up, this full backup will catch it. but then monday's incremental will only back up changes AFTER that full backup. So in a months time, I'll me missing data that changed on saturday morning because I wont have that full backup anymore, and the incremental from monday will not include it.
Is my assumption correct? What are some ways around this? I know one would be to keep the retention period for the offsite tape at 6 months, but at that point, I'm back where I started with wasting tape.
>> Is my assumption correct? What are some ways around this? I know one would be to keep the retention period for the offsite tape at 6 months, but at that point, I'm back where I started with wasting tape.
Couple of ways around this. When you run your weekly backup that you keep onsite (for 6 months) duplicate it to another tape (can use SLP or Vault for this), that way you can get rid of your additional weekly (that you offsite) and your backup on Monday will capture whatever has changed since that last full weekly.
Another cruder way which I don't recommend is copy the policy and have a full backup schedule only, that way your incremental on the other policy does not check this policy/schedule backup but its own last full but the 1st method above is way way superior and easier to manage.
