What tape should I buy to an AIT-2 drive
Rsellberg
more tapes. The question is which AIT version of tapes we should buy?
The Wikipedia says that AIT is both forward and backwards compatible,
but doesn't really specify what that means. Would we gain anything by
getting AIT-3, 4 or 5 tapes in terms of capacity, or should we stick
with AIT-2 tapes?
Or -- is it about time to get a new backup storage system altogether?
//rasmus
Mark F
<rasmus....@daytona.se> wrote:
> We've been using an AIT-2 drive for five years now and need to buy
> more tapes. The question is which AIT version of tapes we should buy?
>
> The Wikipedia says that AIT is both forward and backwards compatible,
I think the density data and the thickness and length of the tapes
vary. I would doubt that you can read the denser data on the older
drives. However, you probably can record in a backwards compatible
manner and read the old tapes.
> but doesn't really specify what that means. Would we gain anything by
> getting AIT-3, 4 or 5 tapes in terms of capacity, or should we stick
> with AIT-2 tapes?
Seems like you could get a speed improvement: go from 12MB/s to 24MB/s
and a capacity improvement of going from 100GB to 400GB. (There is
a change that you can get more data on the tapes now - check Sony
drives.)
I'd say if your disk have grown it is likely to be worthwhile because
of the capacity growth.
I gave up on tape when I went from 60GB disks to 200GB disks 5 years
ago and switched to disk to disk.
Advantages:
1. speed much faster than US$10000 tape drives
2. Getting started cost was much lower (since I would have needed 50
to 100 tapes just to get started.
3. I can backup all my systems at the same time (although I seldom
do more than 2 at a time.
4. In theory I can store the tapes in my attic in northeastern USA;
would not be possible with tapes.
5. incrementally, disks cost less tape. This has been the situation
for 4 or more years even when the cost of a power supply and box
is included. (Although SATA connections are built for more uses
than EIDE and I only use each disk about 10 times, I don't
trust connecting the backup disks directly on a regular basis,
so I put each disk in an external case.)
Disadvantages
1. tapes are smaller than disks since you don't have to shock mount
them. Therefore I could get more tapes capacity in tape in a
safe deposit box. (However I would have had to had to get a
new $10K tape drive by now to keep this up. For disks I just
gradually rotate over from 200GB to 500GB to 1TB drives.)
2. Since I decided not to use the attic and don't want the disks
in the basement, so storing disks is getting to be a problem.
3. getting rid of old disks takes time: have to take apart,
break chips into little pieces, and sandpaper or heat platters.
For old tapes all I had to do was put through a high magnetic
field and cut to about 2-4 inch long pieces using a bolt cutter.
4. Since my storage space is so tight I have to put several human
readable labels on each box, which adds significant time.
5. I have to deal with the overhead of putting each disk in a case.
I also enter all of the serial numbers, revision levels, chip
information that I can find in my files in case there turns out
to be a problem related to a manufacturing plant or whatever.
(I did the same for tapes, but usually there was only 1 or 2
numbers per batch of 40 or so tapes, so it took 5 minutes
for 40 tapes compared with about 30 minutes per disk.
[I actually got 2 free 500 GB disks when 500GB was state of
the art because of a decrease in performance related to a
firmware change. However, the main reason I keep everything
online is so that if there is a problem effecting reliability I can
copy the data.])