On Saturday 02 October 2004 23:15, Jon LaBadie wrote:
>On Sun, Oct 03, 2004 at 03:35:30AM +0200, Thorsten Bremer wrote:
>> Hello,
>>
>> until now I'm using a single DDS-3 DAT-streamer with Amanda and
>> everything works well. But it is annoying for me, to change the
>> tape every day. Sometime I'll forget this or I'm not at home. So
>> it is possible that a lot of backups are collecting on the holding
>> disk.
>>
>> I could buy a used "ADIC FastStor DLT 4000"-tapechanger (For 7
>> cartrigdes, each 20 GB native capacity). Is it possible to use
>> this tapechanger together with Amanda?
>>
>> After reaging the docs I also didn't understand, HOW Amanda could
>> use a tapechanger: Is it possible, that I could say, that he
>> should use 2 tapes per tape-run, to save 40 GB on 2 tapes?
>>
>> Or is a tapechanger only 7 single tapes for Amanda? And the only
>> difference is, that a machine automatically change the tapes every
>> day (instead of me)?
>
>Couple of things here:
>
>If things are collecting on your holding disk, you can move them to
>a tape with "amflush".
>
>You can also set a parameter in amanda.conf, "autoflush" to ?yes or
>?true and during any dump, whatever is left on the holding disk
>will be taped along with the new dump stuff.
>
>Yes, of course you can use a changer. Amanda is used in large
>installations doing hundreds of GB backups daily. They don't
>have someone sitting around waiting to change tapes. Even I
>don't do that in my home office. I have a six position changer
>that does 12GB/tape. I set it to use two tapes -- if it needs
>to use them. I.e. my normal nightly backup is about 7 or 8GB.
>But if something unusual happens, it may take over 12GB. In
>that case it will use a second tape.
>
>To start using a changer you must:
>
>- get the changer recognized by your OS
>- get the tape drive in the changer working with dd, tar, mt, etc.
>- get the changer mechanism working with mtx or some other system
> cmds. - select an appropriate changer script, chg-scsi, chg-zd-mtx,
> chg-mtx or some such.
>- set several parameters in amanda.conf
>- set several parameters in the changer script
>- confirm that you can manipulate the changer with amanda tapes
> using the ammt and amtape commands.
>- confirm that amcheck can find the next tape.
>- do your dumps
And one other minor detail should be mentioned, Jon. Some, but not
all linux distributions disable the multiple lun scsi bus scans in
order to speed up the boot process. Co-incidentally, some changers
have their robot mechanisms located at the same scsi buss address as
the drive itself, but at the next higher logical unit number, or
'lun' in the slang. Those distributions that disable this must have
their kernels re-compiled with this option enabled in order to find
and identify the changers robotics at boot time. Without that, it
won't be found or usable. Red Hat is one such distribution whose
default kernels do not spend the extra (maximum of 49 seconds if the
exact scsi-1 protocol is followed) time during the boot to do this.
My formerly employed Seagate 4586N's were in this category of device.
--
Cheers, Gene
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
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Yahoo.com attorneys please note, additions to this message
by Gene Heskett are:
Copyright 2004 by Maurice Eugene Heskett, all rights reserved.
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