[Pc_Support] 3Ware 7410 v 7500-4 RAID 5

[Jason Boxman]

I just upgraded to a 7500-4, running on a slot by itself on a 64/33 bus.  I'm 
getting some strange numbers from it using bonnie++.  The configuration is 
RAID 5 using 64K stripe with 4 x 120GB WD 8MB/cache disks.  The io scheduler 
used was cfq.  The box was idle in single user mode for all tests.  The disk 
array is presently 60% full and running SGI's XFS filesystem.  (The OS is 
Linux.)  The readahead has been tuned to 1536 * 512 byte sectors, as this 
acheives the best `hdparm -Tt` performance over the default of 256.

I'm curious if these results are within reasonable expectations.  The initial 
55MB/s RAID 5 write was nice, but that isn't consistent.  The reads seem a 
bit slow, too.  Perhaps not near the end of the disk platter, though.

The first test, using a 3GB file size and a 64K chunk size.  The kernel was 
patched with -ck2 which I forgot to change to sys.vm.mapped=33 from the 
default of 66.  The former is supposedly more ideal for servers.  You'll note 
the somewhat better writes over the 7410 benchmarks that follow below.  The 
reads are essentially unchanged.

nebula:~# cat 2.6.11-ck2-nfs4-7500.out | bon_csv2txt
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
nebula      3G:64k           55041  38 17120  15           49181  19 108.6   3
nebula      3G:64k           38089  26 16991  14           49805  19 108.1   3
nebula      3G:64k           37913  26 16511  14           51549  19  87.9   3
nebula      3G:64k           31405  22 16285  14           49670  19 108.3   3
nebula      3G:64k           34692  24 16726  14           53287  20  84.5   2
                   ------Sequential Create------ --------Random Create--------
                   -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min       /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
nebula          16   762  16 +++++ +++  1520  22   655  15 +++++ +++   114   1
nebula          16   814  17 +++++ +++  1704  26   693  15 +++++ +++  1177  22
nebula          16   808  17 +++++ +++  1670  28   714  15 +++++ +++  1108  20
nebula          16  1292  25 +++++ +++  1718  25   867  19 +++++ +++  1359  25
nebula          16  1237  27 +++++ +++  1498  23   757  16 +++++ +++  1033  19

Now, here's the 7410 using the same kernel and array configuration.

nebula:~# cat 2.6.11-ck2-nfs4.out | bon_csv2txt
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
nebula      3G:64k           44943  31 18851  16           47983  19  99.1   3
nebula      3G:64k           30633  20 19846  17           48842  18  97.6   3
nebula      3G:64k           34129  24 20130  17           51255  19  90.2   3
nebula      3G:64k           27469  19 19205  17           48829  19  98.1   3
nebula      3G:64k           33236  22 17465  15           50421  19  82.3   2
                   ------Sequential Create------ --------Random Create--------
                   -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min       /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
nebula          16   706  16 +++++ +++   892  14   622  14 +++++ +++   530   9
nebula          16   845  17 +++++ +++  1035  16   656  15 +++++ +++   607  10
nebula          16   783  17 +++++ +++   816  12   650  14 +++++ +++   585  10
nebula          16   781  17 +++++ +++   674   9   717  16 +++++ +++   537   9
nebula          16   679  15 +++++ +++   826  13   608  13 +++++ +++   445   7

Finally, the 7410 under the 2.6.10 kernel with -ac10 patchset.  The 
performance is far more consistent from pass to pass.  I'm going to retest 
the 7500-4 with 2.6.10-ac10 later.

nebula:~# cat 2.6.10-ac10.out | bon_csv2txt
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
nebula      3G:64k           28435  21 18514  17           60699  25 136.2   4
nebula      3G:64k           25227  21 18478  16           43567  18 151.0   5
nebula      3G:64k           26212  20 18172  16           49778  20 131.5   4
nebula      3G:64k           24929  20 18732  17           53058  22 151.6   5
nebula      3G:64k           24779  20 18752  17           49625  21 170.3   6
                   ------Sequential Create------ --------Random Create--------
                   -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files:max:min       /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
nebula          16   720  16 +++++ +++   915  14   618  14 +++++ +++   461   7
nebula          16   707  16 +++++ +++   673  10   714  16 +++++ +++   409   7
nebula          16   707  16 +++++ +++   783  11   670  15 +++++ +++   635  11
nebula          16   831  17 +++++ +++   682  10   763  17 +++++ +++   448   7
nebula          16   759  17 +++++ +++   918  14   657  15 +++++ +++   448   8

-- 

Jason Boxman
Perl Programmer / *NIX Systems Administrator
Shimberg Center for Affordable Housing | University of Florida
http://edseek.com/ - Linux and FOSS stuff