On Tuesday 02 July 2002 14:36, robinsom wrote: >Michael C. Robinson > >There are many types of tape drives, how does one sort through >all the options available on E-Bay lately ? Which tapes drives >are in good condition and which aren't ? What is the quality of >the various tape drive technologies ? If I wanted an 8 gig TR-4 >for example or better yet a drive that can handle 10-24 gigs on >a single tape what is the best way to narrow one down ? Price is >a big issue, that's why I am looking at tape drives that can > backup the systems I'm running even though they won't have as > much capacity as the harddrives those systems are installed to.
If price is an issue, then your are restricted to travans and dats. >I have heard that VXA is the ultimate because the tapes >can take coffee immersion, is TR-4 still better for backup use >than ATA-100? Apples and oranges, one is a cartridge style and the other a drive bus standard. > What do TR-4 tapes cost ? Too much, dats are cheaper, particularly on ebay. > For how long will >the TR-4 tapes be available since everyone seems to be atempting >to get rid of theirs ? Good Q. The last TR4 drive I had started ripping $40 tapes in two during the recognition phase and came out of service forever after the third tape was destroyed. And I've had a dds2 drive do that too. Its a tossup on drive dependability I think, but dds2 tapes are MUCH cheaper, often less than 3 bucks in ten packs. > What tape drives should be avoided other >than the under 8 gig models ? When do you buy bigger tape drives >verses partition your harddisks into smaller chunks and back up >the data to harddisk(s)/CD=R while the system still goes out to >tape ? By using tar, even 360 gig drives can be broken into manageable pieces for a 4 gig per tape drive, but changers are nice. I have a Seagate CTL-96 with a 4 tape magazine which does these two machines with a bit over 100 gigs of drives just fine. Amanda scatters the level zeros out so they fit the available size quite nicely. One tape per midnight run, change tapes every 3 days as I keep a cleaning tape in slot 4 of the magazine. I use a dumpcycle of 7 with a rotation of 20 tapes. I made an oak pigeonhole box to hold them in order in my woodshop. >TR-4 drives seem to be acquirable in the $35-$50 range, has anyone >tried to stripe multiple tape drives together, do RAID with tape >drives so that five eight gig tapes is presented as say one 40 >gig tape to Amanda ? Promise puts out a controller supported >from the 2.2.19 kernel on for ATA-100 drives which plugs into >a PCI slot and using one IRQ adds two drive channels to the >system for around $30. Maybe over time I could acquire a >second, third... fifth TR-4 eight or ten gig drive. Five >tapes per full backup is still fairly reasonable depending >on the tape size. AFAIK, the striping only works with hard drives, but amanda can do serial access to more than one drive in sequence I believe. I haven't done that, but there may be some here who have, and I'll certainly defer to their experience on that subject. >Is it for certain that Amanda doesn't support multiple tape >backups where a backup set is say four tapes and the drive >can take one at a time ? Amanda can't span a single backup disklist entry accross a multiple tape lashup even in a changer. It WILL goto the next tape, but it will restart the failed filesystem fresh on the next tape, so if its too big, it will burn tapes till you are out of tape. The moral is to adjust your disklist entries so they are smaller than one tape each. For that, du is your friend. >Can software RAID be accomplished if the tape drives are > installed, say five or more total, to two servers ? See above. -- Cheers, Gene AMD K6-III@500mhz 320M Athlon1600XP@1400mhz 512M 99.04% setiathome rank, not too shabby for a WV hillbilly
