At 09:57 AM 8/29/2001, Kurt Yoder wrote:
>Darin Dugan wrote:
><snip>
> > Or you need more tapes!
>
>Thanks for the info. I am probably still a bit foggy on the concepts
>behind "dumpcycle", "runspercycle", and "tapecycle".
>
>Questions:
>
>In my case, I _must_ use at least 6 tapes in order for amanda not to
>overwrite any of its level 0 backups?
>If I wanted to use only 2 tapes, I would need to set "runspercycle" to
>2?
Correct, and only run amdump twice in a given dumpcycle (7 days).
>"tapecycle" must always be >= "runspercycle"?
Yes.
>Are there any advantages to making "tapecycle" > "runspercycle"?
Absolutely. For one, you might want to keep X weeks worth of backups, not
just the previous week. I have a very simple scheme for instance that uses:
dumpcycle 1 weeks
runspercycle 5
tapecycle 10 tapes
Meaning I want to be sure to have a full dump of everything at least once a
week (5 runs), and since I have 10 tapes, I should have two complete cycles
on tape at any given time.
But think worst case (that's why you're doing backups, right?) -- if you
only have tapecycle = runspercycle, when it comes time to use the "first"
tape in the cycle again, you're overwriting what's on it, probably with a
newer copy of the same stuff. If there's a tape error, you're screwed. If
this happens in my cycle, I have the other dumpcycle worth of tapes to
recover from. Though you're probably pretty safe with just one or two tapes
more than runspercycle tapes (see below).
>If I have "tapecycle" at 6, and define 7 tapes in the tapelist, Amanda
>cycles through all 7 tapes, with a level 0 at a minimum of every 6 runs
>(every 7 days, in my case)?
You still want tapecycle to be the actual number of tapes (7). But
runspercycle will only be 6.
If you had:
dumpcycle 1 weeks
runspercycle 6
tapecycle 7 tapes
..you might see something like this for a given host:
(the incrementals might go higher than 1, it's just an example)
Monday tape1 level0
Tuesday tape2 level1
Wednesday tape3 level1
Thursday tape4 level1
Friday tape5 level1
Saturday tape6 level1
Sunday (no backup)
Monday tape7 level0
Tuesday tape1 level1
Wednesday tape2 level1
...
Does that make any more (or less) sense?
Cheers.
--
Darin Dugan
[EMAIL PROTECTED]
