Amanda-Users

Re: Using Amanda without a tape changer

2003-05-22 15:14:50
Subject: Re: Using Amanda without a tape changer
From: Per von Zweigbergk <pvz AT linux DOT se>
To: "Stephen D. Lane" <drsteve AT nature.Berkeley DOT EDU>
Date: Thu, 22 May 2003 21:12:02 +0200
torsdagen den 22 maj 2003 kl 20.06 skrev Stephen D. Lane:

On Thu, May 22, 2003 at 07:23:59PM +0200, Per von Zweigbergk wrote:
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From what I've understood, Amanda should be run from a cron job, for
example at at midnight, once a day. I've also understood that you can
configure Amanda to only run on weekdays.

So, basically, the ideal scenario is to have someone go in to the
server room every morning, remove the ejected tape from the previous
day, and store it in a safe. The operator should then put in the next
tape in the cycle. The operator could even take the tapes home as a
crude off-site backup.

I do this every weekday (without the take-home part :)  The job runs
every weekday morning at 02:03am.  When I come in in the morning (which
varies from 6am to 11am :), the job is done, and the first thing I do
is swap the tape (I find that if I don't do it _first_thing_ it doesn't
always get done...)

What happens if you don't? Will it e-mail you pestering you to change the tape, forcing you to do two tape runs on one day?

Or will it simply drop that run, noting the problem... i.e. just fail gracefully, and try again the next day, effectively delaying the backup?

The reason I ask is, what happens in a school holiday, when nobody is on site working the backup units? Of course, the "proper" solution is to disable the cron job during school holidays, but what is someone forgets?

However, is it possible to tell Amanda to never ever use more than one
tape per day, circumventing the lack of a tape changer or tape
operator? Basically, it might be able to fully dump one filesystem, and
only do incremental dumps on the rest of them, never performing more
than one full dump per tape.

This is also exactly my setup.  One tape per day, 5 (week)days per
week.  We were doing all level zeros, but one of the filesystems has
grown too big to do this, so now we're doing incrementals as well, with
a level zero every other day for each filesystem:

Ah, I think I've finally understood the meaning of "dumpcycle" and "tapecycle" now.

Tapecycle == amount of tapes. Has to be a multiple of dumpcycle for optimal conditions. (?)

Dumpcycle == amount of tapes in a "cycle"... i.e. one extended backup dragging on several days. Each tape will typically contain one or more full backups, as well as incremental backups of most (all?) filesystems.

Correct me if I'm wrong. :-)

--
Per von Zweigbergk <pvz AT e.kth DOT se>