Something on 1TB tapes,

I am not anctious to use a 1TB tape.

1. The extra tape length means longer FWD and RWD times.

2. Having this much data on one tape means that the possibility for a
multisession restore becomes smaller because the number of tapes that can be
mounted for the restore will be minimum. Besides the primary tape, there
will be (or should be) at least one copytape.
We have 9 x 3950e drives (on AIX 4.3), so we have sufficient mount points to
start multisession restores. We have 4 mountpoints per client by default.
This would make no sence if we had all the data one tape for a client. In
our case this would mean we could only restore using two sessions (primary
and copy tape) at a time, thus resulting in longer restore durations for a
client.

3.
Having this much data on one tape also result in a much longer volume
restore in case of a defective tape.

4.
The possibility of multiple clients waiting to access data on a specific
tape because it is already allocated by a client or housekeeping process
increases with such large tapes.

There are probably some more disadvantages, but these concern us the most.

Of course there are also some bright sides to this 1TB tape.
Less mounts, less slots in a library, less offsite rotation. If any can
think of some more advantages, please let us know.


PS: We are waiting for the official release of the 3592 drives. We are
desiring faster drives to shorten our restore windows, but the drives and
tapes have to be at the reliability level of the current 3590E. The
increased storage capacity is not interesting to us.

Just my EUR 0.02

Ilja

-----Oorspronkelijk bericht-----
Van: Richard Sims [mailto:rbs AT BU DOT EDU]
Verzonden: vrijdag 8 augustus 2003 14:56
Aan: ADSM-L AT VM.MARIST DOT EDU
Onderwerp: Re: Fw: NEW Magstar Drive ????


>>Do you have informations about the new Magstar Drive called 3592 ??

>It is not yet officially announced. It ought to be based on the 1 TB
>prototype and compete with STK 9940B.

All the major tape vendors seem to be in the TB race.
As for IBM, see older background info:
        Terabyte cartridge:
         http://www-5.ibm.com/storage/europe/tapenews/index.html
        "The IBM 1TB Tape Roadmap" terabyte cartridge presentation:
         http://www.ckzeto.com.pl/pub/IBM_CKZeto.pdf

Something else to see (see what's really inside a 3590 cartridge, p.20):
   http://www.thic.org/pdf/Oct00/imation.jgoins.001003.pdf

 Richard Sims, BU


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