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Contribs.org Forums => General Discussion => Topic started by: barn on May 30, 2007, 05:42:26 PM
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This is a spinoff of my previous thread: http://forums.contribs.org/index.php?topic=37182.0
<short recap>
When I copy from my xp to sme datadisk a software raid5, the network utilization goes in a distinct sawtooth pattern swingning between 25 and 5 % with a frequency of about 10 seconds. (on a 54mbit wireless)
When I unmounts my raid5 from /home/e-smith/files/ibays/Primary/
so my ibays now is on my single disk OS hd, I then have a consistent high network utilization of 27%.
</short recap>
So obviously something to do with my raid5
smeserver: dual celeron 500mhz, 256mb ram on a abit bp6 motherboard (widely known NOT to be the server mb of all times) with 4 ata ports, 2xata33 and 2xata66.
Only 1 hd per port.
1 hd for OS on the ata33, 10GB
3 in a RAID5 for data, one hd on ata33, two hd on ata66 all 300GB
I have the following questions for you experienced people
1) Should this hardware not be enough to keep up with at 54mbit network datastream ?
2) Can you see any obvious mistakes I have made ?
3) What information would you like to see to help determine the bottleneck, besides the bonnie result ?
4) Would the sawtooth pattern indicate a buffer not working somewhere?
5) The bonnie result below, is that "normal" or expected for mine setup? I have no idea wheter the values are high or low
Version 1.03 ------Sequential Output------ --Sequential Input- --Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
barn 500M 7009 85 24178 38 11613 22 8796 88 26305 28 172.8 3
------Sequential Create------ --------Random Create--------
-Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
16 365 98 +++++ +++ 16365 99 371 98 +++++ +++ 1290 96
barn,500M,7009,85,24178,38,11613,22,8796,88,26305,28,172.8,3,16,365,98,+++++,+++,16365,99,371,98,+++++,+++,1290,96
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one hd on ata33, two hd on ata66
That's for certain not the best option. Most techies know that combining different bus-speeds will only slow the fastest element(s) down. That's ofcourse when the combination can work, sometimes that even is a problem already.
Several times I've read (not fundamented) statements that using 3 disks in a RAID5 configuration isn't good either, should be more.
my 2 cents
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Only 1 hd per port.
1 hd for OS on the ata33,
3 in a RAID5 for data, one hd on ata33, two hd on ata66
as Confucius said, not the best option; I mean, this solution is definitely slow.
1) Should this hardware not be enough to keep up with at 54mbit network datastream ?
and keep in mind that:
- 54Mbit/s is theorical bandwidth.. we are talking about 6.75 MB/s.. in real world if you get 5 MB/s you are really lucky
- 54Mbit/s is total bandwidth you have.. in my personal experience, 3 or more wi-fi connection at the same time (3 or more pc acting on lan) is a "shoot on your foot" situation
- wireless connection is unstable
if your first interest is to serve files really quickly you should:
- get a sata controller and sata disks: keep in mind that pci bus is limited to 133 MB/s (theorical)
- get a wired, 1Gbit/s ethernet adapter
just my 2c
Ciao
Stefano
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I updated my machine with the latest patches (including some samba patches) and now the problem is solved...
To Neonano, I'm not really looking for a fast fileserver, I was interested in knowing why my fileserver had a performance that was much worse than you could expect of that hardware.
Erik
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Conclusion : RAID5 is ok... user was the problem :P