Hi,

I'm spending my time gathering benchmarks of a newly installed Open
Enterprise Linux Server on a Dell PowerEdge 2800 equipped with 8 10 krpm
discs connected to a MegaRAID SCSI 320-2E adapter configured for raid
level 5.
While reading (~200 MBytes/sec) and writing (~160 MBytes/sec) data on xfs
partitions is fast, the server delivers files from nss-pools in an evms-
container with ~4 MBytes/sec. Writing speed is less affected.
Can anybody please tell me what's going on? I've tried disabling
hyperthreading, host adapter cache and switched from write-back to write-
thru without success.

Thanks in advance,

Torsten

For those familiar with the Bonnie++ benchmark program I've appended some
significant outputs.

# write-back enabled, blockdev --setra 16384 /dev/sda, xfs partition
# time bonnie++ -u root -s 16g -n 100:50k -d bonnie/
Using uid:0, gid:0.
Writing with putc()...done
Writing intelligently...done
Rewriting...done
Reading with getc()...done
Reading intelligently...done
start 'em...done...done...done...
Create files in sequential order...done.
Stat files in sequential order...done.
Delete files in sequential order...done.
Create files in random order...done.
Stat files in random order...done.
Delete files in random order...done.
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
dirac 16G 43339 99 168616 27 93345 34 47670 98 213167 33
706.7 2
------Sequential Create------ --------Random Create---
-----
-Create-- --Read--- -Delete-- -Create-- --Read--- -
Delete--
files:max /sec %CP /sec %CP /sec %CP /sec %CP /sec %
CP /sec %CP
100:50:0 8974 98 161382 99 19562 99 8262 97 150152 99
11340 78
dirac,16G,43339,99,168616,27,93345,34,47670,98,213 167,33,706.7,2,100:50:0,
8974,98,161382,99,19562,99,8262,97,150152,99,11340 ,78

real 19m16.209s
user 11m27.171s
sys 3m22.491s

# write-back enabled, blockdev --setra 16384 /dev/sda, nss pool
# time ./bonnie++ -u root -s 16g -n 100:50k -d /media/nss/TEST/bonnie/
Using uid:0, gid:0.
Writing with putc()...done
Writing intelligently...done
Rewriting...done
Reading with getc()...done
Reading intelligently...done
start 'em...done...done...done...
Create files in sequential order...done.
Stat files in sequential order...done.
Delete files in sequential order...done.
Create files in random order...done.
Stat files in random order...done.
Delete files in random order...done.
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
dirac 16G 41687 97 87211 15 2652 0 3642 0 5387 0
273.5 1
------Sequential Create------ --------Random Create---
-----
-Create-- --Read--- -Delete-- -Create-- --Read--- -
Delete--
files:max /sec %CP /sec %CP /sec %CP /sec %CP /sec %
CP /sec %CP
100:50:0 3440 32 309 0 2464 18 2109 19 148 0
339 2
dirac,16G,41687,97,87211,15,2652,0,3642,0,5387,0,2 73.5,1,100:50:0,3440,32,
309,0,2464,18,2109,19,148,0,339,2

real 268m34.797s
user 6m43.356s
sys 1m48.393s


# write-thru, nss pool
# time ./bonnie++ -u root -s 16g -n 100:50k -d /media/nss/TEST/bonnie/
Using uid:0, gid:0.
Writing with putc()...done
Writing intelligently...done
Rewriting...done
Reading with getc()...done
Reading intelligently...done
start 'em...done...done...done...
Create files in sequential order...done.
Stat files in sequential order...done.
Delete files in sequential order...done.
Create files in random order...done.
Stat files in random order...done.
Delete files in random order...done.
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
dirac 16G 15390 35 13373 1 2477 0 3611 0 4649 0
259.7 0
------Sequential Create------ --------Random Create---
-----
-Create-- --Read--- -Delete-- -Create-- --Read--- -
Delete--
files:max /sec %CP /sec %CP /sec %CP /sec %CP /sec %
CP /sec %CP
100:50:0 707 5 295 0 326 2 392 3 141 0
85 0
dirac,16G,15390,35,13373,1,2477,0,3611,0,4649,0,25 9.7,0,100:50:0,707,5,295
,0,326,2,392,3,141,0,85,0

real 339m55.356s
user 6m30.185s
sys 2m11.471s