On Wed February 26 2003 04:40, Raúl Wild-Spain wrote:
>Hi! Jon
>
>> > define tapetype DDS-4-40{
>> > comment "DDS-4 PowerVault with compression"
>>
>> Is this hardware compression? If using software compression,
>> the capacity is still to be listed as ~20GB.
>
>Yes! it is. I think my PowerVault is configured to compress by
> hardware in a ratio of 2:1 (by default). I this case do you think
> can I make use of these values? are these right?
>
>> > DDS-4-20
>>
>> I know dumptypes can include other dumptypes, but can tapetypes
>> do so also. Besides, the speed would differ for HW compression
>> on and off. Then again, the speed value is unused, so what's it
>> matter :) I don't know if filemark size would change.
>
>I saw something like these in my debian-amanda docs ... I will
> review it,
>
>> > Do I suppose this will work properly? Have anyone experience
>> > with DDS-4 tapes and amanda?
>>
>> Lots of people.
>
>;-))
>
>> > dumpcycle 0
>> > runspercycle 2
>>
>> Can you fit two runs into a zero size cycle?
>
>I saw in the documentation that a dumpcycle value of 0 indicates
> to amanda run a full backup with every amdump. So I've tried to
> indicate to amanda " by rotating my 2 tapes you must to do a full
> backup every amdump".
>
>I want that amanda warns by mail ... "needed tape Backup01 ....
> needed tape Backup02" (rotated) and it does a full backup every
> amdump with every tape... how to accomplish this?
>
Set 'tapecycle' to the number of tapes you actually have.
And I concur with the rest of the advice Toomas gave you. You'll
have less trouble in the long run if you shut the hardware
compression off forever, then use software compression only for
those DLE's that will actually compress. You'll get more on the
tape as its better compression, and amanda will know exactly how
much she can put on a tape instead of the SWAG* method you have to
use when using the hardware compressor.
Be aware that turning the compression off on tapes that have already
been written to with it on takes a bit of a walk to do since the
tape, when loaded, tells the drive I'm compressed, and that turns
the drives compression back on regardless of the dip switch
settings.
You basicly have to turn it off when the tape is fully rewound, then
write, using dd, enough data from /dev/zero to force the drive to
flush its buffers, at which point it will update that flag in the
tape header and that tape then becomes an un-compressed tape.
I surround that with some other dd stuff to extract the tape label
first, then do the uncompress routine, rewind and re-write the
label block. That way the stuff in the middle doesn't play with
the old girls mind when she cannot find a tape she knows full well
she did label.
>> That is going to take a long time to convince your boss that
>> amanda is working. One run/week? For testing/demo, why not run
>> it nightly or business nightly?
Amanda works alright, if he has questions, have him join the list
and ask some of us longtime users what we think. We're of course
biased, but the 2 main alternatives are both outragiously priced
compared to free, and considerable more labor intensive on a day to
day basis... Amanda, when properly setup to be run in the hours we
sleep, requires only that the right tapes be in the magazine wheh
she needs them.
Any recovery operation with any software is of course rather labor
intensive, but can be accomplished with nothing more than a bare
metal fresh os install that includes tar, gzip and dd in most
cases. Anything else is just window dressing if push really does
come to shove.
>while I haven't the rest of tapes I must to do backups not only
> for testing but "operative". I thinked that at least doing a
> weekly full backup are ok ... at the moment.
>
>Best regards,
SWAG* Scientific Wild Assed Guess, your trivia fact for the day :-)
--
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz 512M
99.23% setiathome rank, not too shabby for a WV hillbilly
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