Also Sprach Anthony A. D. Talltree: > >100 gigabyte hard disk is less than $200 > > Where? I'm not even aware of a 100G disk being sold. >
Watch out, 1 TB is just around the corner or at least within the next 2-3 years. > >while the last check on high capacity tape drives turned up prices exceeding > >4 times that for maybe a quarter the capacity because advertised tape > >capacity is compressed capacity. > > I think you're kinda missing the point about tape drives. You see, the > tapes are *removable*. You can keep buying new tapes and writing new > data onto them. > The other point is that a tape cartridge is mechanically and electronically simple compared to a hard drive. You can set up hard disks in removable bays and swap out rotations just as with tape. ATA hard drive prices are close to that of tape media prices now. However there are no disk based jukebox or changer solutions that I'm aware of yet. In terms of taking up physical space, a half height disk is bit bigger than 8mm, about the same as 1/4". But I suspect you would need a stabler physical environment. The Ecrix VXATape I use can be immersed in hot coffee (actually I used tea), rinsed, and still come out OK. I don't think any non-mil hard disks can pass that kind of punishment. A hard disk just has many more parts which can fail. > >Worse, tapes don't last, they have a three year shelf life if they are stored > >properly > > Say *what*??? This is absurd. > If you're using 8mm video cassettes in old 8mm Exabyte 8200 or DAT audio tapes in old 4mm DDS, perhaps not so absurd. But modern tape formulations are very sophisticated and have claimed shelf lives of decades (under simulated aging conditions of course unless the media companies have access to a quantum gravity manipulator) and last for thousands to tens of thousands of passes. > >and the tape doesn't physically break when it winds around the spools... > Freak accidents do happen, and there are such things as defective cartridges and drives. But my failures with both SCSI (IBM, Seagate, Quantum, Fujitsu) and IDE (WD, Maxtor, IBM, Seagate) disk have been a lot more numerous than either failed tape drives or media. > >Is it possible to configure Amanda to backup to a harddisk or Raid volume > >instead of a tape? > Yes, even in the 2.4.2 series you can do tricks with holding disks and the reserve parameter. But the 2.4.3 beta series seems to be working well with disk backups. > So, you only want to run backups for a couple of days, then forget about > the whole idea??? > I assume the strategy would be to have multiple backup sets using hard disks rather than tape. > >My last search on tape drives suggested that a high capacity unit that can > >handle 40 gigs per tape is between $800 and $1000 > > Seems plausible - they've certain become a lot cheaper than they used to be. > Ecrix 8mm is about $800 for 33GB uncompressed, DLT1 about $1100. Travan and Onstream are also less than $800. > >I could buy a lot of ATA hard drives for that kinda cash. > Around 6 or so 120GB 5400RPM drives which could go into a 600GB RAID 5 or a 360GB RAID 1+0. > Oh. ATA. I thought you were talking about real disks. That's silly. He's talking about backup and offline storage not primary or near line storage. For those purposes ATA drives are quite real and there are commercial vendors selling ATA backup solutions. If it weren't for cheap ATA drives the researchers at Fermilab, Argonne, Los Alamos, Sandia, NCAR, CERN, LBL, BNL, etc. would have a hard time paying for collecting and storing the data generated by their experiments and simulations. Several radiology departments such as U of Utah's use ATA NAS for storing image data for retrospective studies. ATA drives won't consitute the media for your data center SAN fabric anytime soon (but watch out for serial ATA over the next 5 years) but it most definite has a place right now. > So when you > fill up your cheap ATA disk after a few days, then what do you do? Take > your machine down so you can spend another couple hundred bucks sticking > on a new one? > I would imagine it is no more difficult than using the RAID controller management software to take the disk set offline and swap in the next disk set and bringing it online. ---- C. Chan <[EMAIL PROTECTED]> GPG Public Key registered at pgp.mit.edu "Your Pithy Aphorism Here!" Or finger [EMAIL PROTECTED]
