Hi Lisa, the main points in the AIT vs LTO contest to me are: 1. AIT is a proprietary format dveloped for the then niche market of digital media. It is true it has faster access times than LTO. this is, though, just about the only advantage it can count over LTO. AIT-2 cartridges have 50GB native capacity compared to 100GB for native LTO; AIT-2 can go up to 130GB for compressed capacity while LTO can reach 200GB. AIT-2 has faster access times because the cartridge is smaller, so, on average, the head has to go through a shorter tape length than LTO to get to the first byte of data; but from then on contest is over, as LTO can sustain transfer rates of 15MB/s in native mode and 30MB/s for compressed data while AIT-2 runs, respectively, at 6 and 15.6MB/s. what this means is that when you are transferring big sequential files, as seems to be your case, LTO will "beat the pants off AIT" for overall throughput; an analogy could be 3570 vs 3590. 3570 will get to data before 3590, on average, and then lose out on transfer speed. if you're talking about start/stop and small file transfer then access times are important, otherwise access time is much less of an issue. even in a situation like this last one, LTO has a performance advantage that is quite impressive. anyhow, no one beats 3570's capabilities for start/stop access situations. Generation 2 LTO is, at the moment, under test and will be out in a few months with 200GB native media and 30MB/s, or around that mark, native transfer rate.
2. I don't know of any AIT automated library that can be compared to 3584LTO as to capacity and footprint; you have up to 248TB of native capacity for the 3584, and you can start out with a base frame with up to 12 drives and up to 28TB of native capacity. AIT libraries, if I remember correctly, cannot go further than a few TB(4 I think) and a few drives. If money is a major consideration and you have a homogeneous environment, 3583 would still outpace AIT and cost a lot less than 3584. 3. LTO is an open standard, AIT is proprietary. what this means is that no one company can control LTO's roadmap and force customer's choices. LTO has a set roadmap for the next 4/5 years, and if you don't like IBM tape you just go out and buy HP or STK or whatever and keep using your media. with AIT you do what Sony tells you to. 4. LTO is SAN ready. LTO drives and libraries have Fiber Channel attachment and can be put straight into a Storage Area Network. maybe with a GB Ethernet, your case it seems, this is not an issue but in general it's an important point. TSM can drive these libraries and move data over the SAN with a benefit for LAN traffic (ok, not always as we all know... :-)) . AIT and 3570 are out of the picture here. hope this helps. Cordiali saluti Gianluca Mariani Tivoli TSM GRT EMEA Via Sciangai 53, Roma phones : +39(0)659664598 +393351270554 (mobile) [EMAIL PROTECTED] Lisa Cabanas <[EMAIL PROTECTED] To: [EMAIL PROTECTED] > cc: Sent by: "ADSM: Subject: opinion on AIT vs LTO and 3570 tape technology? Dist Stor Manager" <[EMAIL PROTECTED] .EDU> 05/24/2002 03:15 PM Please respond to "ADSM: Dist Stor Manager" Hello all, I am trying to determine what would be the best tape solution for our ARAN (Automatic Road ANalyzer) van data system. Basically, huge amounts of jpg, mdb and xls data is generated (possibly to the order of 700G per week for 20 weeks, and 20G for the remainder of the weeks). This data will be staged to a 1.55 TB disk array. The customer wants to be able to access the current year's data and the preceding year's data. The "Terabyte" server and two or three processing workstations will be on a private fiber/GigE network, connected by a Catalyst 3550-12G switch. Having only actually experience with 3590 and 3570 drives, I was hoping that someone with experience would be able to give me an opinion (nobody on this list, right ;-) as to which tape technology would best suit their situation -- small footprint, hold 5-10 TB of data to start, scalable, fast access, fast read and write. Money is an object, but for this exercise let's just keep it an abstraction. I had originally thought a 3584 with at least 3 drives would be a good start, but then I started looking at the AIT, whose access time beats the pants off of LTO, and thinking that would be a better solution. I had briefly thought about HSM, but the enormous number of files and directories makes it sound like a really bad idea to me. Any thoughts? I'd also appreciate any ideas about what kind of x86 box would be suited for the TSM server for this system. My only experience sizing servers is with enterprises and RS/6000 servers (I can spend a million here and there for "my" stuff, but this customer has already spend 1.2 million on this "turnkey" solution, and isn't going to be real happy to hear that for them to get their stuff to work and have backups and DR, they need to spend an additional $100,000, but OTOH, that's just deserts for having left IS out of the loop in the purchase in the first place.) TIA and have a wonderful Friday! lisa