On Sun, 2005-04-03 at 00:44 -0500, Jon LaBadie wrote:
> On Fri, Apr 01, 2005 at 10:19:07AM +0200, Erik P. Olsen wrote:
> > On Fri, 2005-04-01 at 02:06 -0500, Jon LaBadie wrote:
> > >
> > > Just for my own interest ...
> > >
> > > Why do you want to do your own scheduling when amanda
> > > often does a far superior job to human defined scheduling.
> >
> > Hm. I would like to challenge this statement.
>
> I don't normally bite on challenges, but I'll take up this one.
I don't want to carry this on ad infinitum, but you asked some
questions.
>
> I hope you read into my statement that I meant amanda vs human,
> both using the amanda 'manager and scheduler' software. I say
> it that way as amanda is not a backup "program".
>
> > It may be true if you have a large network of systems to back
> > up but if you only have one system I doubt if it's true.
>
> Did you miss that amanda is an acronym for:
>
> Advanced Maryland Automatic NETWORK Disk Archiver
In a way I missed it, actually I never payed attention to it.
>
> The needs of a site with one system are very different than those
> of a site with a network of systems for which amanda was intended.
> The fact that it can be used very effectively on a single system
> is a testament to its flexible design.
>
> > Before my switch to Linux I backed up my system
> > (OS/2) on a weekly schedule with one full back-up and four incremental
> > back-ups to one tape only. It worked extremely well, if I crashed my
> > system - which I did very often - it took me about half an hour to
> > recover either using a stand-alone recover program or my maintenance
> > OS/2 if it was alive and I kept an archive of up to 8 weeks of back-ups.
> > Now with Linux and Amanda I use 9 tapes mainly because Amanda won't add
> > today's back-up to yesterday's tape. I could probably do with less tapes
> > but I feel more confident with a large tape pool.
>
> On my home site I do have amanda backup more than one system. But I only
> care about one. The others are "test" systems. I will often reinstall the
> OS from scratch on them. For example, I have HP-UX and Tru64 unix systems
> just because I have clients who use those OS and I like having one available
> to practice with.
>
> The one host I do care about has about 150GB of disk with about 40GB filled.
> One thing that may be different from your environment is that I've broken it
> down into about 15 DLE's. By keeping the DLE's small individually, amanda's
> scheduler can balance when to do level 0's of each DLE throughout the
> dumpcycle
> and lets me do daily backups to a single DDS3 tape. Even when I've downloaded
> a couple of new CD's, amanda adjusts and rebalances its schedule seldom
> requiring two tapes in a day.
>
> I have not worked with OS/2 for over a decade. From that experience I recall
> a backup "program", analogous to dump or tar. I don't recall a backup
> "system"
> one that for example tracked the tapes used and reused them in the correct
> order,
> maintained indexes of files on which tapes, had interactive or batch recovery,
> dynamically and automatically adjusted for missed backups or tape errors,
> allowed for flexibility in time between level 0's on a file system by file
> system
> basis, adjusted the incremental level based on the amount of change in the
> file
> system, ... The OS/2 backup program I remember did nothing more than I can do
> with dump and a little shell scripting. Was there a backup "system" added to
> OS/2 of which I'm unaware? What features of that system did you find useful?
I have been using BackAgain/2 by cds inc. They were bought by Intradyn a
year or two ago and by then the OS/2 version was dropped.
You define a schedule to it which would specify on which time of the day
a specific back-up set should run. The set would specify full or
incremental back-up of one or more drives (partitions). In the process
of doing the back-ups a catalogue of the backed-up files was also
created and related to the tape used and the file no. on the tape as one
back-up set would occupy one tapefile. I would usually leave the tape in
the streamer so when the week was over this tape would keep alle the
back-ups from that week. I had it arranged so that the last back-up of
the week would also eject the tape when it had finished. The tape was
then deposited on a remote location.
The corresponding restore would start with displaying the back-up
catalogue which would show all known tapes with dates for when they were
created (had the first back-up written to it). If you select a tape you
would get a list of all back-up sets on that tape again with timestamp
for when they were written. Selecting a particular back-up set would
then expand into the paths and filenames that were backed up by this
set. After selecting files (all or some) the restore operation could
start provided you had the correct tape mounted.
If for some reason BackAgain/2 would not run to do the restore, a stand
alone version would create a list of all the files backed up to the tape
and you could initiate the restore from that list exactly as from the
saved catalogue.
BackAgain/2 is less sophisticated but still far from the type of dump
and shell script you mention. Incidentally, cds inc. worked on a beta
version for Linux but Intradyn ditched it together with the OS/2 version
and it never reached a usable level.
>
> >
> > I would add that I haven't yet found out how to keep a repository of
> > back-ups of the previous weeks like I was used to with OS/2. I like the
> > safe feeling of having a set of back-up tapes from which I know I can
> > recreate the system as it was on a specific day. Now I just have my 9
> > tapes used in a round Robin fashion.
>
> I too am more confident with a large tape pool, but I have 24 in rotation,
> rather than 9. With that collection I find it simple to recover files as
> of a specific date anytime within the last 3-plus weeks.
>
> I'm a keyboard user from wayback. Literally mice did not exist when I started
> with unix. There are times when I must deal with email using a GUI program
> like
> ThunderBird or (horrors) LookOUT. They make me use the mouse and I hate it.
> I go
> back to my prefered, mouse-less program, mutt as soon as possible. I have
> always
> felt that one should use what meets their needs and with which they are
> comfortable.
Agree.
>
> Amanda is certainly not the answer for every backup requirement. For one
> current
> client I'm using rsync to meet their needs and comfort level. Based on your
> described use of your backups and your lack of comfort with amanda's
> scheduler,
> might not a set of shell scripts and dump or tar be a suitable, perhaps
> superior
> solution for your needs than amanda?
Maybe. However, for the time being I see no alternative to using amanda.
I should probably practise restoring files and partitions so I might get
a more confident feeling with amanda.
--
Regards,
Erik P. Olsen
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