Hi there,
first of all thanx for all the replies concerning my previous mail.
second: hi jakob and here are the single mode bonnie results...
I have done some basic benchmarking in single user mode, and got strange
results:
First of all the setup:
I have a raid-1 partition of 64MB over all 8 disks, as well as a raid-5
over 5 disks a 19GB each.
Now as I have 128MB of RAM, I used the mem=16m for reducing the amount
of memory to get
reasonable results for my raid-1.
Here they are:
-------Sequential Output-------- ---Sequential Input--
--Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block---
--Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU
/sec %CPU
56 4427 56.4 5134 6.7 3787
8.6 6917 82.3 18063 21.4 216.3 4.4
as the memory was already low I decided to run bonnie for the raid5 as
well with a file-size of 128MB:
-------Sequential Output-------- ---Sequential Input--
--Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block---
--Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU
/sec %CPU
128 6845 85.1 24731 20.8 12926 25.0
7896 94.5 36917 24.2 262.3 3.0
Then I ran bonnie two times with the full amount of memory:
-------Sequential Output-------- ---Sequential Input--
--Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block---
--Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU
/sec %CPU
2047 7184 90.2 28856 23.2 17191 32.5
8301 97.5 60630 43.0 201.1 3.7
-------Sequential Output-------- ---Sequential Input--
--Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block---
--Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU
/sec %CPU
2047 7183 90.2 29521 24.1 17086 31.7
8305 97.5 60009 43.3 201.6 2.8
I also used hdparm -t and the raid1 achieves 32MB/s while raid5 achieves
55MB!!!
I am really confused by those results, especially by the reading
performance.
There are 8 disks in the raid1 and only 5 in the raid5, so I would
expect the raid1 beeing lots faster,
as reads are spread in parallel over lots more of disks!!!!!! But it
seems to be alot slower....
Might this be due to the small size of the raid1? Or is it inherent to
raid1 to be a lot slower than raid5???
Or is it because I used a chunksize of 64k on the raid-5, together with
blocksize=4k and stride=16????
While the blocksize on the raid1 is just 1k???
could anybody clear up my confusion a bit????
remo
