On Thu, October 7, 2010 08:21, Lightner, Jeff wrote:
[...]
> Also with "permanent" storage on disk as opposed to tape you
> always take the risk that the remote storage might die and kill all your
> backups.   Tapes can degrade but you are far less likely to lose all
> your offsite tapes at one fell swoop.

Tapes also don't take power and generate heat when they're sitting in the
slot. If you move things around for off-siting, tapes can also take a few
bumps a lot better than hard drive heads.

Also, IIRC, SATA disks's error rate is 10^15, SAS/FC disks are at 10^16,
and LTO tapes are at 10^17.

Regardless of which medium the OP goes with, you should probably have at
least two copies of the data: so one copy on D2D disks, and a second on
another D2D unit; or one on D2D and another on tape; or a copy on two
different tapes.


I think the general best practices is that new deployments should first go
to disk (D2D), and then if you need to keep data for more than "x" weeks,
you clone it to tape. The value of "x" will be different for each
organization. This is mostly because modern tapes are so fast that trying
to got from the client straight to tape (LTO-4 @ 120 MB/s) is very hard to
do without shoe shining.


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