Archived posting to the Leica Users Group, 2010/03/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]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.