Re: RAID backup

[Illtud Daniel <illtud.daniel@llgc.org.uk>]

Effrem Norwood wrote:

> In addition, HSM software costs
> something (even if you write it yourself) on top of the tape infrastructure.
> One customer of ours was quoted 40K per TB of HSM *software* alone.

I've got 25TB uncompressed of HSM here, and it's cost us (ex VAT)
roughly:

£10k for the first 1.6TB (on NT, DLT library)
£18k for the next  6.0TB (on NT, LTO library)
£45k for the next 18.0TB (on Solaris, LTO Library)

...for the software licencing alone. Plus about 10% pa. in support
costs.
You're looking at about 50-60% of the library cost for the HSM software
to manage it (tapes are another thing). Is HSM really that difficult?

It really is a racket, but it's not so much compared with the
cost of re-producing the data (mainly digitized collections).
I'd be happier about it if they were more reliable (libs and s/w).
Disk arrays, on the other hand, would cost us a fortune in
upgrading the cooling - we've had to do this once just because of
the 3-4 TB of online storage we've got, and adding huge exchangers
(and associated pipes) isn't something I want to do much of.

Oh, and having spent much of last night and this morning dealing
with multiple SCSI disk failures, and having seen about 5% of
ours fail in a year, I'm rapidly seeing the light on IDE.

-- 
Illtud Daniel                                 illtud.daniel@llgc.org.uk
Uwch Ddadansoddwr Systemau                       Senior Systems Analyst
Llyfrgell Genedlaethol Cymru                  National Library of Wales
Yn siarad drosof fy hun, nid LlGC   -  Speaking personally, not for NLW