Slow writes using hardware ata raid on older server

[Joseph H. Fry]

I've finally got a clean updated stable FreeBSD box, thank you all who
have invested your time creating documentation that makes it so easy for
us newbies.

Anyway, I had gentoo on the machine for about 10 minutes... Had a
problem with writing to my Megaraid i4 controller... It was terribly
slow (<1MB/sec)!  So I figured I'd try FreeBSD and see how that goes.
I'm no expert, but as far as I can tell Bonnie output (below), things
are not much better.

I only tested with a 100MB file ($ bonnie++ -s 100) because I need to
head to work and didn't want to wait for it to go through a whole 1-2GB
file.

Also below you will find the output from top while bonnie++ was "writing
a byte at a time" and "writing intelligently".  I only include these
because I'm not sure how to read them properly for multiple processors.
>From what I can tell, during the byte at a time write the processor is
pegged, but only about 1/4 used during the intelligent write.

Anyway, I'm stuck now with no idea what to do to fix this problem!  Any
guidance would be appreciated.  (expecially help understanding what the
different values in the bonnie++ output mean)

System:
 Dual PII 233 (smp in kernel) on intel server board
 128MB ECC SDRAM
 LSI MegaRaid i4 ATA RAID Controller (uses amr) in pci slot 1
 Onboard Intel e100PRO
 3Com 3c595
 Adaptec SCSI controller onboard, and one in pci slot
     (I don't have the cable I need to connect my CDROM to
	the onboard SCSI controller so I added one temporarily)



     ------Sequential Output------ --Sequential Input- --Random-
     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
100M    18  99  2172   8  2105  10    54  99 29052  68 373.4  95
       585ms     503ms     613ms     204ms   60668us    3941ms
     ------Sequential Create------ --------Random Create--------
     -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
Files /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
  16  1204  42  5952  96  5136  99  1024  47  6246  99  4649  88
      2547ms     104ms     427us    2682ms   27976us     201ms
1.93c,1.93c,fileserv.thefrys.local,1,1099936265,100M,,18,99,2172,8,2105,
10,54,99,29052,68,373.4,95,16,,,,,1204,42,5952,96,5136,99,1024,47,6246,9
9,4649,88,585ms,503ms,613ms,204ms,60668us,3941ms,2547ms,104ms,427us,2682
ms,27976us,201ms

While writing byte at a
time---------------------------------------------------
last pid:  2317;  load averages:  0.81,  0.30,  0.17    up 0+00:54:58
13:49:24
30 processes:  2 running, 27 sleeping, 1 stopped
CPU states:  4.1% user,  0.0% nice, 45.7% system,  0.3% interrupt, 49.8%
idle
Mem: 16M Active, 368K Inact, 27M Wired, 22M Buf, 77M Free
Swap: 510M Total, 100K Used, 510M Free

  PID USERNAME PRI NICE   SIZE    RES STATE  C   TIME   WCPU    CPU
COMMAND
 2316 jfry     114    0  2380K  1208K CPU1   1   1:37 98.93% 98.19%
bonnie++
 2265 jfry      96    0  2380K  1112K STOP   1   0:05  0.00%  0.00%
bonnie++
  469 jfry      96    0  6092K  2248K select 0   0:01  0.00%  0.00% sshd
 2317 root      96    0  2300K  1368K CPU0   0   0:01  0.00%  0.00% top
 2260 jfry      96    0  6092K  2308K select 1   0:00  0.00%  0.00% sshd
 2261 jfry       8    0  3092K  1588K wait   0   0:00  0.00%  0.00% bash
  379 root      96    0  3440K  2100K select 0   0:00  0.00%  0.00%
sendmail
  474 root      20    0  2296K  1600K pause  0   0:00  0.00%  0.00% csh
  462 root       4    0  6112K  2152K sbwait 0   0:00  0.00%  0.00% sshd
 2257 root       4    0  6112K  2272K sbwait 0   0:00  0.00%  0.00% sshd
.
.
.

While writing
intelligently----------------------------------------------------
last pid:  2321;  load averages:  0.59,  0.41,  0.23    up 0+00:56:44
13:51:10
30 processes:  2 running, 27 sleeping, 1 stopped
CPU states:  0.0% user,  0.0% nice,  4.7% system,  0.2% interrupt, 95.2%
idle
Mem: 16M Active, 59M Inact, 36M Wired, 6656K Cache, 22M Buf, 2448K Free
Swap: 510M Total, 100K Used, 510M Free

  PID USERNAME PRI NICE   SIZE    RES STATE  C   TIME   WCPU    CPU
COMMAND
 2316 jfry      96    0  2380K  1200K CPU1   1   2:48 22.07% 22.07%
bonnie++
 2265 jfry      96    0  2380K  1112K STOP   1   0:05  0.00%  0.00%
bonnie++
  469 jfry      96    0  6092K  2248K select 1   0:01  0.00%  0.00% sshd
 2260 jfry      96    0  6092K  2308K select 1   0:00  0.00%  0.00% sshd
 2261 jfry       8    0  3092K  1588K wait   0   0:00  0.00%  0.00% bash
  379 root      96    0  3440K  2100K select 1   0:00  0.00%  0.00%
sendmail
  474 root      20    0  2296K  1600K pause  1   0:00  0.00%  0.00% csh
  462 root       4    0  6112K  2152K sbwait 0   0:00  0.00%  0.00% sshd
 2257 root       4    0  6112K  2272K sbwait 0   0:00  0.00%  0.00% sshd
 2321 root      96    0  2300K  1352K CPU0   1   0:00  0.00%  0.00% top
.
.
.

Sorry for the long post, I didn't want to leave anything important out.
---- Joe Fry ----
(joe at thefrys.com)