On Wednesday 27 December 2006 07:45, Felipe Garrido wrote:
>Hi, I'm a new in the list.
>
>I've a doubt about backup speed, in my case it's about 500 kb/s and my
>network it's to 100 mb/s. I want to know it's normal or do I have a
>configuration problem ?
>
>Are there a special value in the netusage parameter that I must use in
>it? I tried with a 1024 kbps (default) and 100000 kbps values and the
>result was the same.
>
>Do I need to modify other configuration file to solve may problem ? I
>just modified the amanda.conf and disklist.
>
>thanks for your help
A couple of things can slow you way down.
1. Not using a large enough holding disk will cause amanda to write it
direct to tape. It cannot supply data at a high enough rate to keep the
drive streaming, so the drive runs out of data, stops, then has to backup
and re-queue to the place where it ran out of data, and this is both
very hard on the tape drive and to be avoided at all costs, and a huge
time waster. If the holding disk is used then generally the drive will
start and run continuously at least for the write of that partition or
directory. With amanda being able to do other things, its possible that
once the drive starts, by the time the first file is written, the next
one is ready, so it never stops. This is the ideal scenario.
2. Compressing everything. Compression, successful or not, is time
consuming. Trying to compress something which is already compressed
(that directory full of rpms and tar.gz(.bz2) stuff will probably expand
slightly) is just time wasting exersize for the cpu to keep it warmed up.
We have space heaters for this I think.
Also, on a smaller system where everything is on the same spindle(drive)
will either force amanda to serialize, or if spindle numbers aren't being
used, will result in time wasting hammering of the seek mechanisms of the
drive as amanda tries to backup 3 or 4 partitions on the same drive at
the same time. For the drives sake, one should use spindle numbers in
the disklist entries. Even on single drive systems.
So now the question is: How to fix it? The above are general in nature,
but suggest what one should do to alleviate it. Here, with 3 drives, one
of which is vtapes, around 80GB of data is usually finished in an hour or
so. That's incrementals of course for 74% of it, so the actual backup on
any one night runs in teh 6GB range,
--
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)
Yahoo.com and AOL/TW attorneys please note, additions to the above
message by Gene Heskett are:
Copyright 2006 by Maurice Eugene Heskett, all rights reserved.
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