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.
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