Adaptect raid performance with FreeBSD

[Mike Jakubik]

> -----Original Message-----
> From: owner-freebsd-stable at freebsd.org 
> [mailto:owner-freebsd-stable at freebsd.org] On Behalf Of 
> lists at mediumgreen.com
> Sent: Wednesday, January 14, 2004 10:11 AM
> To: freebsd-stable at freebsd.org
> Subject: Re: Adaptect raid performance with FreeBSD 
> 
> I think I heard Raymond Wiker say:
> >Ari Suutari writes:
> > > dd if=/dev/rda1s1a of=/dev/null bs=1m count=100
> > > 100+0 records in
> > > 100+0 records out
> > > 104857600 bytes transferred in 4.193832 secs (25002814 bytes/sec)
> > > 
> > > So, I get only about 25MB/s. Shouldn't I be getting 
> something like 
> > > 70 MB/s, or even more since there are two disks that can 
> server read 
> > > requests ?
> 
> 
> FWIW, on my mylex controller w/ raid 5 I'm getting:
> 
> # dd if=/dev/da0s1g of=/dev/null bs=1m count=100
> 100+0 records in
> 100+0 records out
> 104857600 bytes transferred in 3.707196 secs (28284882 bytes/sec)
> 
> 
> and my dell perc3/dc (raid 5) is getting:
> 
> # dd if=/dev/amrd0s2e of=/dev/null bs=1m count=100
> 100+0 records in
> 100+0 records out
> 104857600 bytes transferred in 2.133522 secs (49147653 bytes/sec)

This sounds pretty poor for SCSI raid. Here are my results on a single
Maxtor ATA drive.

CPU: AMD Athlon(tm) Processor (1410.21-MHz 686-class CPU)
ad0: 76345MB <MAXTOR 6L080L4> [155114/16/63] at ata0-master UDMA100

# dd if=/dev/rad0s1a of=/dev/null bs=1m count=100
100+0 records in
100+0 records out
104857600 bytes transferred in 2.484640 secs (42202333 bytes/sec)

5 dd's running simultaneously show the following in iostast.

      tty             ad0              ad2              ad4             cpu
   0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0  0 100
   1  119 128.00 129 16.09   0.00   0  0.00   0.00   0  0.00   0  0  1  2 98
   0   77 128.00 424 52.97   0.00   0  0.00   0.00   0  0.00   0  0  5  2 93
   0   77 128.00 424 52.97   0.00   0  0.00   0.00   0  0.00   0  0  0  2 98
   0   77 128.00 423 52.85   0.00   0  0.00   0.00   0  0.00   0  0  1  2 97
   0   77 128.00 424 52.97   0.00   0  0.00   0.00   0  0.00   0  0  1  2 97
   0   77 128.00 423 52.85   0.00   0  0.00   0.00   0  0.00   0  0  0  2 98
   0   77 128.00 424 52.97   0.00   0  0.00   0.00   0  0.00   0  0  1  3 96
   0   77 128.00 424 52.97   0.00   0  0.00   0.00   0  0.00   0  0  0  2 98
   0   77 128.00 423 52.85   0.00   0  0.00   0.00   0  0.00   1  0  1  2 96
   0   77 128.00 424 52.97   0.00   0  0.00   0.00   0  0.00   0  0  2  1 98
   0  924 128.00  21  2.60   0.00   0  0.00   0.00   0  0.00   1  0  1  0 98
   0   77  0.00   0  0.00   0.00   0  0.00   0.00   0  0.00   0  0  0  0 100