On Monday 29 December 2003 13:47, Andrew Hall wrote: >OK..:). Please forgive if I have used incorrect terminology, so I > ask again for my own clarification. Will amanda ever be able to > write to the same tape a few days in a row, without having to spool > to a holding disk? > >Say I have an AIT-2 50/100G tape, yet I only am using 20G of data. > I could fit a full, plus a weeks worth of inc's on a single tape. > >If this is your design decision, mind if I ask why? Are there > dangers in this type of theory? Just curious. > >Thanks again! > >Drew
In that event, and this is commonly done, do not insert a tape till Monday evening, or some other arbitrary day of the week, and configure the holding disk with enough usable space that it can hold a weeks worth of runs. The keyword to set and define is "reserved" in the holding disk group. Put the keyword string "autoflush yes" in your amanda.conf also. Then when it finds a tape on monday night, it will first flush the acumulated backups and then proceed with the new one. Please note though, that you stand to lose a whole weeks backups if the system gets a tunmmy ache. The design decision is because amanda has absolutely no guarantee that someone will not eject the tape, or otherwise mess with the tapes position, from one days run to the next. So amanda is designed to do 2 things: 1: rewind the tape and read the label to make sure its the right tape in the sequence to use next, doing this with each days invocation. This in itself destroys the location you get from an 'mt -f device tell' between last nights run and tonights. 2. Because not all tape drives can reliably do an 'mt -f device seof' to restore that location, and it would be a total loss to write over last nights backup with tonights, the chance of doing that is never taken. Hence, amanda will never attempt to append to a tape. It *must* know that it has the tapes undivided attention during the duration of a run. To that end, if the drive has a door lock command or ioctl, it is used to prevent you from ejecting the tape in mid-run. Its inconvienient for some, but infinitly safer for all this way. -- Cheers, Gene AMD [EMAIL PROTECTED] 320M [EMAIL PROTECTED] 512M 99.22% setiathome rank, not too shabby for a WV hillbilly Yahoo.com attornies please note, additions to this message by Gene Heskett are: Copyright 2003 by Maurice Eugene Heskett, all rights reserved.
