Backup Solutions

[Christopher Browne]

On 8/30/07, Neil Watson <tlug-neil-8agRmHhQ+n2CxnSzwYWP7Q at public.gmane.org> wrote:
> I still think that rotating tapes is cheaper and safer than disks.  For
> speed many companies are moving to disk backups for quick restores but,
> these disk backups are copied to tapes for off site storage and
> rotation.

The thing is, the improvements in disk drive technology have NOT been
generally getting applied to tape drive technology, with the result
that the speed and size of disk drives have been growing steadily,
whereas the same is not true for tape.

- Travan maxxes out at 20GB for ~$500
- LTO maxxes out at 400GB, and costs thousand$
- DAT maxxes out at 80GB, for ~$1K
- AIT maxxes out at 400GB, for thousand$

And generally speaking, media for tape drives costs only very slightly
less, per GB, than SATA/IDE drives.

You can buy a dozen USB-connected drives with enclosures for about the
same price as a DAT/AIT drive plus a dozen tapes.  Periodically,
you'll have to replace disk drives, but the same was true for tapes...

> It is a common for companies to fail in planning for long term data
> recovery.  They pay lip service to laws like SOX by storing tapes off
> site for years.  However, they do not ensure that they have the ability
> to recover that data from tape when the time comes.  Five years from now
> will they be able to read the tape or the Exchange 5.5 data stored on
> it?

Will they be able to buy a tape drive that can still read the media?

If they're backing up on a disk drive, then there is the very
significant merit that they can, at any time, plug one of the backups
into a computer, mount it, and have some hope of connecting it to
(say) an Exchange server to test the ability to read the data.

> To this end one needs to create a data retention policy to cover all
> aspects of backup and restore.  What will be backed up?  How long will
> the data be kept?  How will the data be restored to the user the on the
> day before it is officially expired?  Working to that end, if you buy
> another tape drive I suggest you buy two and put one in storage with
> your off site tapes.

All good questions.

If these aren't answered, then it doesn't matter what media you're
using to do the backups, you're likely to have useless results.
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