Yes, you CAN DO off site reclaimation with one drive. The way it should be
set up is in the tsm books (online version) or one of the redbooks. I set it
ones up, and it work. Slowly but it work. The compagny I work for has divert
libraries with 6 to 10 drives (and still growing), but some of the clients I
have to do locally. So I went and have a look at TSM and working with one
drive. Short story, IT CAN BE DONE.
-----Oorspronkelijk bericht-----
Van: GUILLAUMONT Etienne [mailto:eguillau AT RGB-TECHNOLOGIE DOT FR]
Verzonden: woensdag 2 oktober 2002 16:09
Aan: ADSM-L AT VM.MARIST DOT EDU
Onderwerp: Re: Off site copy with one drive???
The only small things I would need to be able to use TSM with a single
drive library is to have the ability of having a next storage pool on a
copy pool, I must be possible to do as it is already done on a backup
storage pool. And the ability of using a disk reclaim storage pool for
offsite copy pool reclaim.
My solutions would be the following :
A backup pool on tape in the library
1 or more copy pools in a vault with only one or two empty tapes in the
library.
Each day, I backup on tape and make a copy on one of the copy pools, if an
offsite tape is to be reclaimed, TSM copies the files in the disk reclaim
pool from the backup pool and then switch tapes to write to the copy pool
tapes
Except the fact that if my drive goes down, I must wait until it is
repaired (with a three drives library, you will still have this problem if
the whole library goes down), the functionalities would be the same than
with two tapes. Except for performances but everyone don't need
performances in backup and restore. But everyone needs reliability in
backups and TSM is very good for that.
I agree with you that if there is no other possibility, it's better to buy
and expensive library than having unreliable backups. But TSM requires very
few modifications to be fully usable with a single drive library. Don't
forget that most other softwares work perfectly with a single drive
library, and some of them must probably be as good as TSM or not far from
it.
Excuse me for having been insulting but each time I hear "There's no way to
do it" it upsets me. (And my english is not that good, I probably could
have found a more adequate word than "stupid")
Etienne GUILLAUMONT
e-mail : etienne AT rgb-technologie DOT fr
RGB Technologie
Parc d'Innovation, Batiment PYTHAGORE
11 Rue Jean SAPIDUS
67400 ILLKIRCH
Tél : 03 90 40 60 60
Fax : 03 90 40 60 61
Mark
Stapleton To: ADSM-L AT VM.MARIST DOT EDU
<stapleto@BER cc:
BEE.COM> Subject: Re: Off site copy with
one drive???
Sent by:
"ADSM: Dist
Stor Manager"
<ADSM-L AT VM DOT MA
RIST.EDU>
02/10/02
15:26
Please
respond to
"ADSM: Dist
Stor Manager"
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU]On Behalf Of
GUILLAUMONT Etienne
> I hope you will excuse me to be so direct but I think that you last
answer
> is stupid,
Actually, I won't excuse you, and there's no need to be insulting.
> did you ever look at the price of a single drive library
> compared to a three drive library ?
Indeed I have. I install and configure them for a living.
> And I don't talk of the fact that most
> 3 drives libraries require the advanced library TSM feature which
> multiplies the price of TSM by 4 ! But I think this is why you talk of a
> BIG favour, it is because the price is BIG. If you compare the whole
> solution, you will see that the whole solution has a price
> multiplied bye 4
> or more which makes it unaffordable for most companies.
I guess it all comes down to what's more important--the cost of a proper
library vs. the ability to dependably make multiple backups of your
valuable
data.
> I completely agree with you that a three drive (or at least two drives)
> library is far more practical with TSM but it is very expensive. In
> addition, what is the use of buying a 2 or 3 Tbytes library when you need
> only 200 or 300 Gbytes.
You buy a smaller, scaled-down library. I stated earlier that single-drive
libraries were pretty much worthless. I should have said that they "were
pretty much worthless when used with TSM".
> I saw in this list some people saying that TSM is only for big companies
> and that if you can't afford a 2 drives library, you should'nt buy TSM.
I don't ever recall anyone on this mailing list claiming that TSM is only
for big companies. Is TSM expensive? Yes. But if I want to run a high-end
computer game, I don't go out a buy a cheap video card, either.
> I also disagree with that, TSM has some functionalities which make
> it usefull
> also for small companies (I had another storage software before and for
> example, I saw that with TSM, I could reduce the number of tapes to buy,
> and then to manage by 2 or 3)
Indeed it has.
> I think it wouldn't be a lot of work for Tivoli just to add a few
> functionnalities which would allow small companies to use it with a
single
> drive or with a small library.
And just how do you propose to use a single drive to run space reclamation
on copy pool tapes? (This was the original question for this thread.) Copy
pool reclamation uses files from the primary tape pool, and you just can't
access two tapes at a time with one drive. If you're going to use a single
drive, you're either going to have to forgo copy pools, or live with the
fact that you can't run reclaims on them. (You can just delete copy pool
volumes; they'll just get recreated the next time you do a storage pool
backup.
> Don't forget that many companies uses only a
> single drive on each server and if you talk to them of the price of TSM
> with advanced library and a 3 drives library, they laugh.
Let 'em laugh. If you can't afford a multi-drive library, you just can't
afford it. You're just not going to get to use TSM's full functionality.
--
Mark Stapleton (stapleton AT berbee DOT com)
Certified TSM consultant
Certified AIX system engineer
MCSE
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