Ben Elliston wrote:
> Hi.
>
> You wrote in the Amanda FAQ:
>
> ``This can be wasteful, specially if you have a small amount of data to back
> up, but expensive large-capacity tapes. One possible approach is to run
> amdump with tapes only, say once a week, to perform full backups, and run it
> without tape on the other days, so that it performs incremental backups and
> stores them in the holding disk. Once or twice a week, you flush all backups
> in the holding disk to a single tape.''
>
> Can you expand on this?
No or wrong or active tape in drive means for amanda: put the backups
into holding disk and leave them there.
If you specify reserve 100 in config it will degrade any level 0 backups
to level 1. If not it takes only 100-reserveoption percent for level 0
in holding disk.
If you leave out the tape lets say for a week, all the backups will be
in the holding disk, provided its large enough. Then if the right tape
is in drive it will happily put a lot of level 0 backups onto it, due as
they are.
When the holding disk holds some amount of incrementals, you place
another valid tape in drive and flush them manually.
> What should I use for the cycle parameters in
> amanda.conf?
No change there. The cycles just reflect the time you want to keep
backups and the frequency you want to have a complete backup.
Just make sure your holding disk is big enough.
> How should I flush the incrementals in the holding disk to
> tape? Thanks,
simply run amflush configname (as your amanda user) with a valid tape
for your configuration in drive.
>
> Ben
Or you can try another approach:
You can use two different configs. Not really different, as the only
changes are the name and the pattern for the label string.
This way you could have
without_tape and with_tape as confignames and all the tapes labelled for
config with_tape
on weekdays you run amdump with config without_tape and on weekends with
with_tape.
as it would be in my crontab:
0 22 * * 1-6 amdump without_tape
0 22 * * 7 amdump with_tape
Because the configs share the same directorys and index files etc. you
can amflush the without_tape backups with the with_tape configuration
and it's tapes.
AND you can leave the tape in drive.
I don't know exactly if with_tape would _always_ make level 0 backups,
but I believe it would try, because of the dumpcycle parameter.
To be sure you can set dumpcycle to 0, so the level 0 dumps will always
be due when amdump runs.
(Note that reserve should be 100 for weekdays, as you want incrementals.
Or you play with the nofull and the new incronly options)
I'm doing with a variation of that method, and I'm quite happy with it.
Simon Mayr
