I'm going to cross-post this text on the Amanda and Bacula lists.
Apologies in advance if you see this twice.

Our company is about to provide centralised backups for several pools of
backup data of between 1 and 15TB in size. Each pool changes daily but
backups to tape will only occur once a month for each pool.

The backup tape format is to be LT04 and we have a second-hand Dell
PowerVault 124T 16 tape autoloader to work with currently. Backup from a
pool may be taken off a Linux LVM (or hopefully soon a BTRFS) snapshot
ensuring that the source data does not change during the backup process.
We have the possibility of pre-preparing backup or compressed images if
this is advisable.

An important aspect of the system is that the tapes should be readable
for 12 years, by other parties if necessary. From this point of view we
like the idea of providing a CD with each tape set of the software
needed to extract the contents, together with a listing of the enclosed
files in a UTF8 text file. We will be required to audit each backup set
by successfully extracting files from tape.

We are very familiar with working on the command-line in Linux,
Postgresql and Python.

As we have not run backup to tape on Linux before I would be very
grateful to receive advice on what approach members of this list would
take to meeting the above requirements.

Many thanks,
Rory

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