Bernard, I based my suggestion on technologies already available on the market today and known to me. I have no access to such internal data as you have. Neither I knew when StorageTek will release next edition of 9940 nor I can say when IBM will make commercial product from their 1 TB lab cartridge. Thank you for sharing the info with us.
Zlatko Krastev IT Consultant Please respond to "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> Sent by: "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] cc: Subject: Re: IBM vs. Storage Tek Another technology to consider is STK 9940B, GA in the September timeframe, extremely high capacity with enterprise class reliability and performance characteristics. 200GB native capacity 30MB/sec native transfer rate 2GB FC and fabric capable Enterprise class duty cycle characteristics Significantly lower effective media cost vs. LTO (uses same media as 9940A) Comparable search/positioning characteristics to 9940A Thanks, Bernie Survoy Consulting Systems Engineer Phone: 216 615-9324 Cell: 330 321-3787 StorageTek Information made Powerful -----Original Message----- From: Zlatko Krastev/ACIT [mailto:[EMAIL PROTECTED]] Sent: August 16, 2002 10:43 PM Subject: Re: IBM vs. Storage Tek My personal recommendation is to evaluate upgrade to 3590H. I am surprised why this is not the IBM's first proposal. Arguments: LTO definitely is downgrade to what you have now both in terms of performance and reliability as others already answered. Higher capacity per volume and much lower price are main advantages. Former will soon change while the latter will never change. For large data streams native rate of LTO (15MB/s) is higher than for 3590B (9MB/s) and slightly above 3590E/3590H (14MB/s). Utilizing different compression algorithm on compressed data the rate of 3590B (27MB/s) is comparable to LTO (30MB/s) while 3590E/H definitely outperforms it (42MB/s). But for smaller files you have to count also mount time and there 3590s are more than two times faster than LTO. With LTO is much harder to get some benefit from filespace collocation while this can help in many cases with high-end tape drives. Reliability of LTO is not bad but cannot compare to 3590/9x40. Bigger volume ought not be such a problem for reclamation - it should be nearly the same would you reclaim 3 volumes 100 GB each or 30 volumes 10 GB each for same average percentage. If LTO gets damaged you for sure will have to restore much more. But this is true whenever you go to *any* higher capacity technology - just the same for 3590E/H or 9940. Same remark for collocation - it is not related to technology but only to capacity of the cartridges. There are two ways to prevent it - stay with (older) lower capacity technology or limit maxscratch forcing more than one node's data to be put on a volume. And you can always define several pools with different maxscratch settings so it ought not be a big problem. Upgrade to 3590H would be more expensive than brand new LTO but you will get much better product. All remarks about performance and reliability ought to be enough to justify higher price. You will not be forced to get rid of those 5500 cartridges and buy new LTO ones. You will get 60 GB per tape as from 9940A. SAN-attachment also is not a problem with fiber drives and dual-ports (vs. single ported LTO) add to reliability. StorageTek silos with 9840/9940 drives are very good products. If we want to compare apples with apples we have to compare them with IBM 3494 + 3590B/E/H drives. Comparison with DLT or LTO would be apples vs. oranges. So the statement "it costs twice" returns nothing useful. Count again the need for new 9x40 cartridges and plan what will do with old 3590 ones. But for me this would be replacement of Mercedes with Cadillac - both are very good, both are very expensive and both give the same results with different vendor's approach. Zlatko Krastev IT Consultant Please respond to "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> Sent by: "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] cc: Subject: 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 [EMAIL PROTECTED] (717)975-8338
