I also appreciate Mr. Railbeck feedback. We have been using an all disk primary
backup pool for over 4 years now and recently switch our copy pool to all disk
NAS located at a remote site for DR. While Mr. Railbeck's comments may be
correct in theory, for me in practice they don't hold up. For instance he said
"This (no reclamation for random access storage pools) can cause inefficient
utilization of the disk space over time" , my experience shows random access is
still more efficient use of space than sequential due to the fact that I set my
reclaim threshold for sequential media at 50%. For me setting the reclaim
threshold higher is not worth the additional overhead.
Also of note is Mr. Rialbeck's statement "We have not done a lot of testing on
this, so this can not be taken as a definitive statement". I suggest anyone
interested in an all disk storage pool environment to test it for themselves.
Considering TCO, that is, dirt cheap ATA's drives, lightening speed restores,
and an incredibility simple DR solution, an all disk storage pool environment
has been a real winner with us. It's made me happy, the users happy, and most
importantly management happy.
Thanks,
john underdown
SYNOVUS
Phone:706-644-7592
-----Original Message-----
Date: Mon, 9 Jun 2003 17:04:07 -0400
From: "Talafous, John G." <Talafous AT TIMKEN DOT COM>
Subject: Re: anyone using ATA disk systems
Mr. Raibeck,
I appreciate your feedback and, being involved in IT for some 30 years, I
understand the technical challenges involved. That is why I posted the
question. With the falling cost of disk architecture, a disk to disk backup
alternative seems to be coming close to rivaling disk to tape as a backup
alternative. Especially when dealing with some of the more sophisticated
tape solutions that involve the mainframe/zArchitecture.
If I size my TSM solution such that I can recover 'x' number of
application servers in a given number of hours, then I will require a
certain number of tape drives based on the data transfer rate of each tape
drive. Hence, any recovery process in DR mode is limited to the number of
tape drives available. Ouch!!! With disk to disk, my limitation is the TSM
server and the network.
Add to the mix the fact that tape data transfer speeds are less than SCSI
and/or ATA data transfer speeds and the thought is that with capacity of
disk architectures increasing rapidly and the price currently lower than
tape, it makes sense to back up everything to disk!!! Faster and lower cost!
So, I/we would appreciate IBM Tivoli's support of this concept.
With all the pressure on budgets and all these jobs NAFTAing, I MUST
arrive at the best solution! Thanks for your consideration.
John G. Talafous IS Technical Principal
The Timken Company Global Software Support
P.O. Box 6927 Data Management
1835 Dueber Ave. S.W. Phone: (330)-471-3390
Canton, Ohio USA 44706-0927 Fax : (330)-471-4034
talafous AT timken DOT com http://www.timken.com
-----Original Message-----
From: Andrew Raibeck [mailto:storman AT US.IBM DOT COM]
Sent: Monday, June 09, 2003 1:33 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: anyone using ATA disk systems
Addendum: I as I said earlier, we continue to study the matter. Possible
outcomes include enhancements that will enable TSM to function better in
an all disk storage pool environment, although we make no commitments at
this time.
Regards,
Andy
Andy Raibeck
IBM Software Group
Tivoli Storage Manager Client Development
Internal Notes e-mail: Andrew Raibeck/Tucson/IBM@IBMUS
Internet e-mail: storman AT us.ibm DOT com
The only dumb question is the one that goes unasked.
The command line is your friend.
"Good enough" is the enemy of excellence.
|
