Murray Taylor wrote:
BTW
I know tapetype, what is amtatype??
I had a day off yesterday, and so did my brain :-)
And I was typing the message with one hand (and in the other hand my 2
month old baby).
It is "amtapetype", the new program in Amanda 2.4.4b1.
And in my explanation below, if you get the default length of 1 Gb, then
amtapetype writes not 1000 but 10000 files of 10 Mbyte each in the first
pass (because it believes that 10Mbyte * 100 files = 1 Gbyte).
etc. etc.
On Wed, 19 Feb 2003 00:22, Paul Bijnens wrote:
Dave Ewall wrote:
I ran Tapetype on my Ultrium drive (came with a Dell Poweredge server),
and got this:
define tapetype Ultrium {
comment "Ultrium"
length 101632 mbytes
filemark 0 kbytes
speed 13884 kbytes
}
If I remember right, it took about an hour to run if I gave it the right
parameters. I played with the parameters for a few days (in spare time)
before I got it right though... otherwise, it was running for daysIt s
It should take about:
2 passes * (101632 * 1024 kbytes / 13884 kbytes/sec) /pass
= 14990 sec
or about 4 hours 10 min.
+ some time to rewind and stop/start at filemarks.
The stop/start at filemarks is what makes it slower than expected. The
more files it has to write, the slower.
The important parameter is a good guess of the length:
amtatype -s 100g
would do it fine. The program writes 100 files of 1 Gbyte each. If you
let it the default size estimate of 1Gbyte, then the program will write
files of 100 Mbyte hoping it will have about 100 when hitting end of
tape. But now it needs to write 1000 files. The second pass writes
files of half the size, and will need to write 2000 files. Now the
start/stop time becomes sigificant in the total runtime, and the program
becomes slow.
--
Paul Bijnens, Xplanation Tel +32 16 397.511
Technologielaan 21 bus 2, B-3001 Leuven, BELGIUM Fax +32 16 397.512
http://www.xplanation.com/ email: Paul.Bijnens AT xplanation DOT com
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