SW-RAID0 Performance problems

From: Andreas Peter (ujq7@rz.uni-karlsruhe.de)
Date: Fri Apr 13 2001 - 06:47:30 EST

Hi,
I've successfully set up SW-RAID0 with Kernel 2.4.3 and Raidtools 0.9.
I did this to increase the performance of my HD, but nothig happens.
The hdparm results:
hdparm -t /dev/md0 : 20.25 MB/sec
hdparm -t /dev/hda : 20.51 MB/sec
hdaprm -t /dev/hdc : 20.71 MB/sec

I thougt the performnace of RAID0 should near 40MB/sec.
I played with different chunk-sizes, but the result was everytime the same.
The drives are both Maxtor DiamondMax VL40, 30GB, DMA on.
No other drive is attached on the bus.

Here are also some bonnie++ results:

-- RAID-0 --
-- chunk-size=16 --

Version 1.01 ------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
debian 1G 7416 99 14277 20 7498 10 6942 90 27007 20 113.0 1
                       ------Sequential Create------ --------Random Create--------
                      -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
                 16 267 99 +++++ +++ 10968 100 269 99 +++++ +++ 1388 99

-- chunk-size=32 --

Version 1.01 ------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
debian 1G 7396 99 14075 20 7469 10 6945 90 26960 20 133.7 1
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
                 16 265 100 +++++ +++ 10695 99 267 99 +++++ +++ 1447 100

-- Single HD /dev/hdc1 --

Version 1.01 ------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
debian 1G 7173 96 11055 13 5038 6 5999 78 29146 21 90.7 1
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
                 16 272 100 +++++ +++ 10482 99 274 99 +++++ +++ 1437 100

Are there known performanace problems with 2.4.3, or is it necessary to
apply patches to the kernel?
Or did I something wrong??
Thank you for every hint!

Andreas 

-- 
Andreas Peter *** ujq7@rz.uni-karlsruhe.de

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This archive was generated by hypermail 2b29 : Sun Apr 15 2001 - 21:00:21 EST