I think you also need to consider duty cycles - how much data does TSM push per day, how hard will you be pushing the tape drives.
In my discussions with IBM & STK, they BOTH say that the LTO drives are not designed to replace "enterprise class" drives, meaning the 3590's or 9840's. The construction is just not designed to take the beating that the 3590's or 9840's are. Which is why the drives are more expensive than LTO (DUH). The 3590 & 9840 drives also have some performance characteristics that make them faster than LTO for some operations (like dealing with a lot of start/stop activity). This is neither good or bad. It's a matter of matching your hardware to your environment. We have a TSM server here with some 9840 drives that run OVER 10 HOURS per drive per day. That is quite a beating. Nothing short of a 9840 or 3590 will do. We have two other TSM environments that are much more sedate. Those would do fine with LTO. Something else to consider. ************************************************************************ Wanda Prather The Johns Hopkins Applied Physics Lab 443-778-8769 [EMAIL PROTECTED] "Intelligence has much less practical application than you'd think" - Scott Adams/Dilbert ************************************************************************ -----Original Message----- From: Guillaume Gilbert [mailto:[EMAIL PROTECTED]] Sent: Wednesday, July 24, 2002 4:38 PM To: [EMAIL PROTECTED] Subject: Réf. : LTO Tape OR 9840 Hi Joni I personnaly prefer 9840's but the bean counters love the LTO because the drives are very much lower cost and the cost per GB is lower. The 9840 is probably the best drive/tape on the market today. The native thruput of 9840b's is 20 mb/sec while the LTO is 16 mb/sec. The start/stop on the 9840 is considerably faster than the LTO. Reclaiming a 40 - 50 % full LTO took me 4 to 5 hours (client compressed data) and I can move data a full 9840 (client compressed data) in less than 30 minutes. I reclaim my 9840 at 40% and do about 20 to 30 tapes a day easy. Is your STK silo a 9310 or a 5500? Or is it one of the smaller ones like a L180 or L700? With the big silos the mount time is not much of an issue. The seek time will be faster with the 9840. As for tape life, I've been working with 9840s for a little over a year without any tape failure. I look at it this way : if I lose a 9840, I loose a max of 20 GB of data. With an LTO, I loose 5 times that. Guillaume Gilbert CGI Canada Joni Moyer <[EMAIL PROTECTED]>@VM.MARIST.EDU> on 2002-07-24 15:17:32 Veuillez répondre à "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> Envoyé par : "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> Pour : [EMAIL PROTECTED] cc : Objet : LTO Tape OR 9840 Hello everyone! The environment here is going to be changing soon... We will be moving off of the mainframe and onto an AIX server that will be on our SAN. We will have 1 STK silo for the tapes for 2 TSM servers. Right now we are considering IBM's LTO or STK's 9840. I was just wondering if anyone out there has had experience with either one and if so, what are the pro's and con's of them? Has anyone that has worked with LTO know how long it takes to recover a bad tape? Considering that they are 100GB tapes, it was assumed that it would take 5 times as long as it does to recover a Magstar 3590(20 GB). And also, do the tapes get damaged easily or is that all a matter of handling them to take them offsite to vaults? Thank you!!!! Joni Moyer Associate Systems Programmer [EMAIL PROTECTED] (717)975-8338
