Folks -- I've been using amanda for a couple of years now on Sun hardware (DLT8000-based L9 tape library, with stctl as the tape changer controller). It's worked great, but I'm nearing capacity with the current system and trying to decide whether to expand (another L9 and a load of DLT-IV and Sun-bought holding disk) or switch to another hardware platform and tape format. I was hoping folks could take a look at my suggested new setup, and offer advice, warnings, horror stories, etc.
The amanda control host would be a smallish Linux rackmount job with attached SCSI+RAID disk enclosure -- currently I'm considering a Dell PowerEdge 1650 (1U, PIII-based) with a Dell PowerVault 220S (3U, 14 x 36 GB Ultra160 SCSI disks + PERC/3 RAID controller). Doing a RAID-5 + hot spare across the fourteen disks would give me 400 "real" GB (1024^3) of holding disk. I'd use RedHat Linux 7.3 for the OS. Main reason for picking Dell and RedHat over other PC/Linux options is just that they're the standard for my group these days. For a tape library controller, I'm hoping that either the "mtx" or "scsi-changer" drivers will be able to control the library hardware (see below). My standard backup "depth" has been to try to have around two weeks of "dailies", with a short dumpcycle to get a high proportion of level zeroes onto the tapes (more for convenience of restores than anything else). I've also got a separate "offsite" rotation of all level zeroes, run once a week, with about four weeks of depth, in case the data center ever burns down. With my current backups, I wind up having the operators flip the DLT tapes in the L9 every day, which causes lots of dropped tapes and more wear and tear on the library. I'd like to get away from that, and wind up with a library capacity that lets me keep the daily rotation loaded all the time, with an extra slot so I can load the offsite tape for the week on Monday morning and then forget about it until the next Monday. After poking around, the AIT3 tape format from Sony feels like a nice direction in which to move (alternatives being sticking with DLT, or moving to SDLT or Ultrium). I don't know much about hardware vendors for AIT3 libraries, but two of my candidates are the QualStar CLS-4216 (2U, with 1 AIT3 drive and 16 tape slots) or the Overland LibraryPro (4U-ish, with 1 AIT3 drive and 19 tape slots). Either of these would let me load two weeks worth of tapes and a weekly offsite. I'm assuming I'd wind up with two libraries and two amanda rotations with about 200+ GB of data in each. I could go with software 2:1 compression to save on holding disk, or dump to disk uncompressed and then try to get the mythic 2.6:1 hardware compression advertised for the AIT3 format. Does the above sound reasonable? terrible? Have I missed any compatibility issues, and does anyone use a setup similar to this one? Thanks for any and all advice, -mgs
