I picked and chose from 3 of Bart Brasher's postings:
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> Is there a way I can get amanda to tell me how many tapes I need?
Let me try some numbers:
> I have about 170Gb of data to be backed up right now
I'm assuming that is not disk capacity, but total disk space used already.
>From your amadmin balance output:
> TOTAL 57 125748810 125749696 12574969 (estimated 10 runs per
amanda has seen 57 file systems (disklist entries) containing 126GB of the 170,
but you said some have never been backed up, so that is reasonable.
> dumpcycle 2 weeks
> runspercycle 10
Using the 170GB number and 10 runs, that is nominally 20GB on average of full
backups per run. With over 60 disklist entries to spread over the 10 runs,
amanda will probably be able to stick reasonably close to that number.
Unless 1 or 3 are really huge.
> ... , and I'm actually generating more than 40Gb per day of level 1,
So that seems to me you should have an average of approximately 60GB of data
being backed up daily, 20GB level 0's plus 40GB incrementals.
Conservatively you estimate your tapes at 40GB capacity.
> I have ... 40Gb DLT8000 tapes
So it sounds to me like 2 tapes per day is reasonable. And if the data is
reasonably compressible, many days one would be enough.
I do have concerns about your holding disk and the way you are "trying" to
use multiple tapes.
The reserve situation has been addressed by others.
But about your holding disk, amcheck says:
> Holding disk /tmp/amanda/dump: 57492036 KB disk space available, that's plenty.
And yet 57GB is not plenty when you are backing up an average of 60GB.
Your use of your tapes is ?imaginative?.
> I lie to amanda, and tell here there's one tape of size 80Gb, and run
> amflush manually each day when I get in to the office.
> runtapes 1
> tapetype DLT8000x2
> define tapetype DLT8000x2 {
> comment "Two tapes on DLT8000 40 Gb Hardware Compression"
> length 78000 mbytes
> filemark 2362 kbytes
> speed 20000 kps
> }
Do you then amlabel pairs of tapes the same - nah, sorry.
You use them in pairs and have 22 tapes, so shouldn't you actually list
your tapecycle as 11, not 22? Of course that is only 1 more than a
dumpcycle. Cutting it kinda close.
Couldn't you give a correct tape type, specify runtapes as 2. With
modifications to chg-manual, I'll bet you could have the first tape in
the drive at the start of the overnight amdump and then finish only
the second tape the next morning.
--
Jon H. LaBadie [EMAIL PROTECTED]
JG Computing
4455 Province Line Road (609) 252-0159
Princeton, NJ 08540-4322 (609) 683-7220 (fax)
