OK...I see that as documented here: http://wiki.zmanda.com/index.php/FAQ:Why_does_Amanda_not_append_to_a_tape%3F
This would seem to allow full tape utilization without having to resort to vtapes...I'm pretty sure I was already doing this and it didn't work reliably...will try again. As I understand it, it would seem that the holding disk needs to be *slightly* larger than the largest "tape" you are going to write to. I would also seem that setting your backup files size to something pretty granular (e.g. 1GB, 5GB or at most 10GB) would also help ensure you make full use of a "tape". Now I've got a MASSIVE amount of IO capacity (300MB/s for the holding disk) and since each "tape" is connected via its own dedicated SAS/SATA port I've got about 100MB/s for as many tapes as I load at the same time (e.g. if I load 5 I could be writing as much as 500MB/s)...of course this means I have to split all of the source disks I'm backup up from across multiple Amanda configs, right? But then that complicates things, I presume I need a dedicated holding disk for each config? or can multiple configs share the same holding disk? If the former, then I presume what I really want is holding disks like this: drive 1 - 2TB - holding1 (DailySet1) drive 2 - 2TB - holding2 (DailySet2) drive 3 - 2TB - holding3 (DailySet3) drive 4 - 2TB - holding4 (DailySet4) But now I'm confused...if I have all my flush params set to 100% and my holding disk EQUALS the size of a backup "tape", how am I ever going to reach the 100% threshold (would seem I would always be short by a few GBs)??? Perhaps I should go back to a stripped holding disk and carve out multiple holding disks inside that and essentially oversubscribe the strip a bit, for example: Stripe (drive1, drive2, drive3) - 6TB total /hold/hold1 - config in amanda as 2.1TB /hold/hold2 - 2.1TB /hold/hold3 - 2.1TB /hold/hold4 - 2.1TB ...or something like that...not sure if I can get away with oversubscribing the Stripe that much...if not I think 4 2TB drives would work fine. This would allow any holding disk to easily grow to 2.0TB and thus fill a 2TB (or 1.5TB) "tape" fully...yes/no? +---------------------------------------------------------------------- |This was sent by baldw...@mynetwatchman.com via Backup Central. |Forward SPAM to ab...@backupcentral.com. +----------------------------------------------------------------------
