Hi Joni
What you wrote sums it up in terms of performance and reliability. I think the
same way you do as far as LTO goes. It is very good for small enterprises and
full backups.
But I don't think it fits TSM very well, espacially in a large environnement
like yours. Almost everyday I talk about it to our analysts so I won't have to
support a
large TSM server (400 clients) with those tapes. My 9840a's are very good. The
B's are even better. The Gresham solution is easier to implement in a lanless
backup
strategy. Compare the cost of DTELM licencing to that of TSM Library Sharing. I
don't have any figures but I bet the two are pretty close.
Sure with STK tapes you'll have more tapes but a Powderhorn can take it. Before
the 9840, we had over 3000 EE-tapes (1.6GB native) in our Powderhorn just for
TSM with
only 4 drives. I was doing reclamation by copying the tapes to disk storage
pool. With the 9840 I reclaim at 40% and do about 30 a day starting at 9:30 and
it usually
finishes before I get off work. In 1 year I had 1 (one) tape failure and no
drive failures. That's pretty reliable. I'm thinking the 3590 is as reliable.
Remember, you always get what you pay for.
Guillaume Gilbert
CGI Canada
Joni Moyer <joni.moyer AT HIGHMARK DOT COM>@VM.MARIST.EDU> on 2002-08-15
09:29:48
Veuillez répondre à "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
Envoyé par : "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
Pour : ADSM-L AT VM.MARIST DOT EDU
cc :
Objet : IBM vs. Storage Tek
Hello,
I know I've asked about this before, but now I have more information so I
hope someone out there has done this. Here is my environment for TSM.
Right now it is on the mainframe and we are using 3590 Magstars. We have a
production and a test TSM server and each has about 13 drives and a total
of 5,500 tapes used for onsite and offsite tape pools between the 2
systems. Two scenarios are being considered (either way TSM is being moved
onto our SAN environment with approximately 20 SAN backup clients and 250
LAN backup clients and will be on SUN servers instead of the mainframe)
Here is what I estimated I would need for tapes:
3590 9840 9940A LTO
10 GB 20 GB 60 GB 100 GB
Production
Onsite 1375 689 231 140
Offsite 1600 800 268 161
Total 2975 1489 499 301
Test
Onsite 963 483 163 101
Offsite 1324 664 223 135
Total 2287 1147 386 236
Grand
Total 5262 2636 885 537
1. IBM's solution is to give us a 3584 library with 3 frames and use LTO
tape drives. This only holds 880 tapes and from my calculations I will
need about 600 tapes plus enough tapes for a scratch pool. My concern is
that LTO cannot handle what our environment needs. LTO holds 100 GB
(native), but when a tape is damaged or needs to be reclaimed the time it
takes to do either process would take quite some time in my estimation.
Also, I was told that LTO is good for full volume backups and restores, but
that it has a decrease in performance when doing file restores, archives
and starting and stopping of sessions, which is a majority of what our
company does with TSM. Has anyone gone from a 3590 tape to LTO? Isn't
this going backwards in performance and reliability? Also, with
collocation, isn't a lot of tape space wasted because you can only put one
server per volume?
2. STK 9840B midpoint load(20 GB) or 9940A(60 GB) in our Powderhorn silo
that would be directly attached to the SAN. From what I gather, these
tapes are very robust like the 3590's, but the cost for this solution is
double IBM's LTO. We would also need Gresham licenses for all of the SAN
backed up clients(20).
Does anyone know of any sites/contacts that could tell me the
advantages/disadvantages of either solution? Any opinions would be greatly
appreciated.
Thanks!!!!
Joni Moyer
Associate Systems Programmer
joni.moyer AT highmark DOT com
(717)975-8338
|