Sorry about the messy copy/paste and no threading - for some reason, I
am on the digest of this list - which I don't like and I haven't found a
way to switch from digest to regular emails...so I read the replies from
Gene/Jon and have follow up...
Gene>
> From the above figures its apparent that A: you're not using the
> latest amtapetype, and B: hardware compression is on.
> Useing hardware compression does this list of things:
> Now, if I've convinced you to turn the hardware smuncher off,
> be aware that a DDS tape, once written to with the compressor
> on, is a bit of a problem child to get it to turn off because
> even though you have reset the dipswitch to off mode, the
> tape recognition cycle when you put the tape into the drive,
> will find that flag on the tape and turn it back on for you.
> Very thoughtfull of the drive, NOT!
> What this means is that to get rid of that flag on such a
> tape, one must do something like this:
> mt -f /dev/nst0 rewind
> # now, save the tapes label
> dd if=/dev/st0 of=scratch bs=32k
> # turn off the compression
> mt -f /dev/st0 defcompression off (or -1 for some mt's)
> mt -f /dev/st0 compression off
> # now put the label back using non-rewinding device
> dd if=scratch of=/dev/nst0 bs=32k
> # and flush the drives buffers to force the flag update
> dd if=/dev/zero of=/dev/st0 bs=32k count=130 (or more)
> # now read the label out to stdout to show you its still ok
> # but please note that all the other data on the tape will be gone
> dd if=/dev/st0
> Re-run amtapetype after doing the sequence above to your
> test tape. See the man page and give it the correct
> estimated size as an argument. That will speed it up some.
> Then do it to all tapes that are to be reused as you
> cycle them thru the drive until you've treated all your
> tapes to the no-compression as shown above. Or you could
> make a script out of it and do it before fireing off amanda.
> But be aware that the above requires root access, whereas
> amanda will get her own, so its an "su amanda -c 'amdump
> /configname/'" in your root script.
----
OK - understood - I am not one to piss into the wind...hardware
compression off is the plan - Macintosh/Windows roots - hardware
compression was easy, Linux/Amanda requires much more low level
configuration than I had planned to ever learn but there is gain so I
endure and bow to your great pearls of wisdom. Before I go any further,
THANK YOU Gene & Jon for your terrific replies
Anyway, I presume that I don't need the tapes, can wipe out curinfo &
tapelist for this config and start from scratch, erase the tapes and not
worry about dd'ing the headers off and back onto the tapes.
Thus my specific questions...
1 - if I issue the command to turn off hardware compression...
# mt /dev/nst0 compression off (or -1)
or is it
# mt /dev/st0 compression off (or -1)
Must I do that each time I restart (as in add to rc.local?)
Must I do that before I run any amdump?
How often do I have to turn compression off?
2 - isn't the chg-manual script supposed to send an email to the mailto
addresses in the amanda.conf when it needs another tape?
3 - is there any 'user' interface for Amanda such as a webmin module
<http://www.webmin.com> or must I script out common operations for
users?
lastly, in reference to Jon's reply...
>> Do I adjust the numbers of the 'length?'
>> Does the length of 9675 seem small for a DDS-3 (125 meter
>> / supposedly
>> 12/24 Gigabyte or does formatting / filemarks / labels
>> /etc cut 20%?
> Adjusting the value of a meaningless number is an exercise
> in futility.
Exercises in futility is something that I seem to do well. Sorry but
some of the documentation is spread out and I didn't find it
all/comprehend it all but I'm getting it slowly.
Thanks,
Craig
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