On Tuesday 17 August 2004 09:19, Mark Wormgoor wrote: >Hi, > >I have recently switched to Amanda for making my backups (yes, that >means I'm new to Amanda). I have several small (/etc, /var/lib/rpm, >/var/spool/mail) directories to backup and one large directory > (/home). I would like to back these up to disk. I have followed > the HOWTO and all is working fine. > >But... how do I setup my tapes? If I create 16 5GB tapes with a >dumpcycle of 7 days, I cannot store /home on them (not enough > space). But if I create 8 10GB tapes, I will only have one full > backup per dumpcycle, where I would prefer two. And, my tapes would > be mostly empty (only a full backup requires 10GB). > >What is a wise strategy? Can I use two tapes in parallel in a disk >backup? How? I am using chg-disk as my tpchanger. Are there > better solutions? > >Kind regards,
The best strategy comes from useing a whole bunch of small entries in your disklist, thereby giving amanda the maximum ability to shuffle things around in its quest to put about the same amount on the (tapes/virtual tapes on disk) each time it runs. I have my disklist broken up so that no one entry (there are about 50) is over 400-600 megabytes (except /usr/src of course, it was larger) and most are less than 200 megabytes, some much less. With this degree of granularity, amanda can quite happily load every tape, every night, to over 95% of its capacity. Sometimes the email will tell you that something that was backed up with level 0 just a couple of days ago, is being done again 3 or 4 days early, but thats just amanda shuffling the schedule for best fit over the length of a dumpcycle. If you start getting messages that so and so was delayed by a day, and it happens more than once per dumpcycle, then its time to either get bigger tapes, or add a day to the dumpcycle. This also means that for quicker settling, one should when first starting out, or making major additions to the disklist, only expose about a bit less than one tapes worth of _new_ data per run of amanda. I *was* running dds2 tapes (4Gb uncompressed), 28 of them, with a dumpcycle that varied from 3 to 4 full backups of everything on hand at any one time. Unforch, my 5th changer in this long term saga finally died about 6 weeks ago, so I'm 'rsync'ing the really precious stuff to a second drive that I mount just for that purpose, then unmount it again when the rsync run is done. All scripted of course. But I'm looking for something I can run as cheaply as the dds2 changers to replace it, unforch that pretty much rules out a big library since I'm more or less retired & looking at my 70th in about 6 weeks. I don't have $5G plus for a big library. I'm considering re-writeable dvd's as the price per disk isn't that much more (only about 2x per disk) than I was paying for the tapes on ebay. But I'd need about 30, maybe more, and haven't dropped the card enough times to setup a library of dvd disks yet. Write once are cheap enough for long time archiving, but these are intended to be recycled at the end of the tapecyle and the re-writeables seem to jump off the shelf before I get there. I'm giving Circuit City and Staples small amounts of hell everytime I'm there but it hasn't done me much good so far. Like you, with only about 20 on hand, its too close to the dumpcycle to suit me. I want at least 2 generations of fulls on hand. >Mark Wormgoor -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) 99.24% setiathome rank, not too shabby for a WV hillbilly Yahoo.com attorneys please note, additions to this message by Gene Heskett are: Copyright 2004 by Maurice Eugene Heskett, all rights reserved.
