[kiryandil]

Why only keep backups for 6 months? Tape is cheap.

Because they're lying?

Tape was cheap 15 years ago, when we were archiving our files.

They're lying like rugs. Tyrannical rugs.

[The_Media_never_lie]

Another big lie: it is extremely complicated to extract LL’s emails from the backups. Show me an IT guy who says retrieving backup emails is extremely complicated. Bet one cannot be found.

[zeugma]

Tape is cheap, though these days hard disks are cheaper in a relative sense.

Back when I was a tape monkey in a data center, here's the system I used.

• Daily incrementals. Backs up everything that changed since the last full backup. Have 2 rotations of a full weeks worth. i.e., you have 2 separate sets for Monday, 2 sets for Tuesday, etc)
• Weekly backup - 5 sets of tapes on a weekly rotation. Every 5th time they were used, (not every 5 weeks because of monthlies - see below) you they were  overwritten. This is a full system backup
• Monthy. Full backups kept for 5 years.

The most data you could lose was the intra-day work that happened since the end of one backup and  the end of another. We could go back 5 years for stuff that was not even financial/legal stuff, but just data that it was possible we might want for research purposes.

I do essentially the same thing at home now with an external drive, except it uses Rsync to limit the amount of data required to maintain the different rotations. I occasionally swap out the external drive, though probably not as often as I should. If I were smart, I'd do that right after the monthly is done.

None of this is rocket science, and all of the above was using 9-track tape, stored offsite until the week it was being returned to be used. 

When they say they've "lost" the emails, they are blatantly lying. They may have actively searched out and destroyed the evidence of thier crimes, but it wasn't simply 'lost' in a hardware failure.