Archived posting to the Leica Users Group, 2010/03/24
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]John Nebel wrote: > Dennis, > > Yes, HP was bragging about T10 a while back, thanks for reminding me. > > The issue of multiple formats is an interesting one. We have DLT3, > DLT4, SDLT1, SDLT2, and LTO4 and must be able to read them all. It > wasn't too long ago that there were 9-track tapes in the archive. I think you mean your tape library must be able to read them all. The DLT & SDLT are Quantum's proprietary format, the cartridges don't work in LTO drives. LTO is an open format and drives must pass an interchangeability test to bear the LTO logo. Your tape library should be able to migrate data from the DLT & SDLT media to LTO media. I would think it is a goal to do that by some future date. Whether or not Quantum wants you to migrate from SDLT to LTO is another question! I think when you need tape that LTO is the only choice due to the multiple vendors that help keep prices down. I don't think anyone here on the LUG has so much data they need tape, at this point. Perhaps if Tina gets her 1.5 million film images scanned! Dennis > > LTO4 is probably a good choice for a PC at this point as the drives > and media are pretty cheap. > > John > > Dennis wrote: >> A big advantage of automation, tape libraries, is that with multiple >> drives you can automate migration of data to newer format tapes. In >> John's case he can ujpgrade some of the drives to LTO-5 or LTO-6 and >> add the new higher capacity media and migrate data from the LTO-4 >> media to newer media. When you have many terrabytes of data those >> expensive tape drives start to look pretty desirable. >> >> John; the interface between the automation and the drives used to be >> pretty simple with each automation vendor having their own protocols. >> It has been replaced by a standardized protocol that is under the >> INCITS T10 technical committee. If you want to take a look you can >> download draft standards from the t10.org website. PM me if you do >> and I'll guide you to the right spot(s). >> >> >> John Nebel wrote: >>> Spencer, >>> >>> LTO4 tapes are around $30/ea on ebay in lots of 20. The drives are >>> $thousands, but one drive is infinite offline storage. >>> >>> John >>> >>> Spencer Cheng wrote: >>>> Hi John, >>>> >>>> Very nice. The techie in me says "Cool. Can I borrow it?" :) >>>> >>>> I am not sure I want to know how much those LT04 tapes are. :)) >>>> >>>> My home built NAS cost about $1K including 5.5Tb of disk space. >>>> Good enough for my purpose. Nowhere near as cool as yours though. >>>> >>>> Regards, >>>> Spencer >>>> >>>> On Mar 22, 2010, at 20:22, John Nebel wrote: >>>> >>>>> Hi Spencer, >>>>> >>>>> Your post motivated me to photo part of the internals of a backup >>>>> device, a robotic tape library with a petabyte capacity (600+ 1.6 >>>>> terabyte tapes). >>>>> >>>>> http://www.ancientmoney.org/library.html >>>>> >>>>> If one has the space, time, and and a bit of knowledge, things >>>>> like this can be acquired fairly inexpensively. I had installed a >>>>> couple of LTO4 tape drives, and someone in Quantum service became >>>>> upset and canceled a $20K/year maintenance contract - one is not >>>>> allowed to work on their own equipment under their rules. >>>>> Generally speaking, it is a reasonable position, however, not in >>>>> every case. Quantum left me stranded with a broken hoist cable for >>>>> the robotics platform, and I'd made the mistake of power-cycling >>>>> the library and nothing would come online. The tape drive >>>>> enclosures have electronic switches which only allow the drives to >>>>> power up after the robotic diagnostics succeed. $10 for stainless >>>>> steel aircraft cable (not for use in aircraft, of course) and $50 >>>>> for cutting and swaging tools and it was back in operation. >>>>> >>>>> Quantum gave a credit for the prepaid maintenance which bought a >>>>> pallet of tapes. Ultimately Quantum was apologetic and showed >>>>> good integrity. >>>>> >>>>> I found a used library for $5.5K which works perfectly and >>>>> provides the necessary backup for the backup device. >>>>> >>>>> In the process I looked into the library's controller and found >>>>> its OS quite comforting, Linux. The OCP is a tiny flat screen >>>>> xterm with a four button keyboard and the library runs Apache for >>>>> its web interface. I think the interface between the robotics and >>>>> the processor is serial with simple ascii commands. The interface >>>>> between the tape drives and the outside is fibre channel through >>>>> bridge cards. One talks to the Linux processor over ethernet, >>>>> however, there is also a fibre channel card in the controller so >>>>> that robotic commands may be sent via scsi over fc by the hosts. >>>> >>>> >>>> _______________________________________________ >>>> Leica Users Group. >>>> See http://leica-users.org/mailman/listinfo/lug for more information >>> >>> _______________________________________________ >>> Leica Users Group. >>> See http://leica-users.org/mailman/listinfo/lug for more information >>> >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >