On Monday 13 January 2003 02:36, Nitesh Kumar A. wrote:
>Hai Jon:
>
>I haven't compared AMANDA with other backup utilities extensively.
>
>The main reason is - People in our university are using ADSM. I
> have been using AMANDA for sometime on my machine. I need to have
> a nice reason for my university for switching over to AMANDA.
>
>Few nice reasons could be it's a freebie, works well on
> heterogeneous systems, open source, etc.
>
>But I am also looking for advantages of Amanda over ADSM, which is
> a licensed one. Some reasons technically.. . about why we should
> prefer Amanda over ADSM or in fact any other utility. There are
> also other freebies like Amanda too.
>
Amanda is designed for the absolute minimum of operator
intervention, with the operators duties relegated to making sure
the next tape, or set of tapes if you have a changer robot, are in
place for the next scheduled backup session that you tell cron to
run at 1am when hopefully everything is quiet.
Amanda uses 3 basic variables in it config file to control how
amanda runs. These are:
dumpcycle=how many days amanda has to do a full on everything
runspercycle= how many times it will be run in the above time
tapecycle=how many tapes you have in the rotation, working minimum
would be at least 2 runspercycle
Amanda doesn't *do* a *fixed* backup schedule per sei, but once the
run schedule above is specified, and the disklist file filled in
with what amanda is to backup, amanda will move the day of the
fulls on each individual path around so they will level out the
tape useage per run, normally by advancing the full by a day or
more till its happy. You might need to help at startup by bringing
in about a tapes worth of data per run when getting started, else
she might try to do more than a tapes worth on those first runs
trying to play catchup.
This generally takes about a 'tapecycle' of runs to fully stabilize.
What that means for instance is that I have about 35 gigs spread
out over 110 gigs worth of drives, with a 'dumpcycle' setting of 5
days. It puts about 3 gigs on each 4gig DDS2 tape after
compressing that which will compress. Some directories are quite
sparse, and will smunch to less than 10% of the original size.
I couldn't put this system on a single magazine of tapes (4) if all
fulls were done on the same day, so this is very economical to me.
We had a mesage from another user about 2 weeks back who was using
it on a 2.2 terrabyte database system, so apparently it scales
nicely. I don't believe he said how big his drive (must have been a
library) was though.
Amanda is also still being actively developed, and some of us on
this list (me included) are always running the latest 'snapshot'.
Compare that to arkeia, who license to run a tape library will run
you about $2.2k and is more of a pretty face than it is usefull, or
bru, also expensive but considerably less. All the others that
I've looked at are just wannabees, but most of them are also
freebies. However, to be fair, this is the first I've heard of
ADSM so I cannot pass judgement on it either way.
Recovery with an amanda generated tape is a piece of cake once the
system has been reinstalled far enough to have a copy of tar (and
gzip if the data is compressed) and dd or some workalike utilities
available, the rest of the amanda install is optional. I think you
can get that on a boot floppy.
No magic cookies that label the tape as useable only with the
proprietary software that made the tape are used. I've done a full
recovery with nothing but tar, gunzip and dd here.
You sometimes have to rethink the phsychology(sp) of how to do
backups before you can appreciate amanda, but once the concepts are
understood, it makes perfect sense. Those that are determined to
do a full on friday night, and incrementals the rest of the week
are going to find that it can be done, but it tends to reduce
amanda's ability to do the job right and wastes tape.
Give her a try, and if there are questions, there are people here
who are better than I at giving precise answers.
[...]
--
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz 512M
99.22% setiathome rank, not too shabby for a WV hillbilly
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