7.1-PRERELEASE: arcmsr write performance problem

[Mike Tancsa]

At 12:50 PM 12/15/2008, Paul MacKenzie wrote:
> > Any suggestions on where to look next?  Are there obvious candidates?
>
>After weeks of working on this I now believe that anything that taxes
>the writing to the hard drives causes the system CPU numbers to spike
>through the roof (approx 80% usage) and the server grinds to a halt. And
>I also see wide swings in the System CPU usage. It reminds me of the
>QUOTA issue I had with 6.2 where the system usage was really high and it
>was the QUOTA code that was broken.

Hi,
         I dont have a box in the lab I can test a lot with right 
now, but I do have a couple of these cards in customer servers and 
write performance seems ok

This is an AMD64 box, 8G RAM
7.1-PRERELEASE FreeBSD 7.1-PRERELEASE #2: Tue Sep 23 09:25:02 EDT 2008
running a lot of postgres queries right now

[ns8]# dd if=/dev/zero of=/var/tmp/test count=1000 bs=1024k
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 10.265211 secs (102148508 bytes/sec)
[ns8]#

which seems reasonable for raw write performance.

If you bring up the little Areca web app, are there any errors about 
the array?  When you created the raid sets, what params did you use ?

The above is on
Volume Capacity 320.0GB
SCSI Ch/Id/Lun 0/0/0
Raid Level Raid 1+0
Stripe Size 64KBytes
Block Size 512Bytes
Member Disks 4
Cache Mode Write Back
Tagged Queuing Enabled
Volume State Normal



[ns8]# vmstat -i
interrupt                          total       rate
irq4: sio0                         57065          0
irq17: em1                    3989494045        554
irq18: arcmsr0                 558098657         77
cpu0: timer                  14381393929       2000
irq256: em0                     22763077          3
cpu1: timer                  14381384902       1999
Total                        33333191675       4635
[ns8]#

arcmsr0: <Areca SATA Host Adapter RAID Controller
 > mem 0xe8600000-0xe8600fff,0xe8000000-0xe83fffff irq 18 at device 
14.0 on pci2
ARECA RAID ADAPTER0: Driver Version 1.20.00.15 2007-10-07
ARECA RAID ADAPTER0: FIRMWARE VERSION V1.43 2007-4-17
arcmsr0: [ITHREAD]
.....
Waiting 5 seconds for SCSI devices to settle
(probe16:arcmsr0:0:16:0): inquiry data fails comparison at DV1 step
da0 at arcmsr0 bus 0 target 0 lun 0
da0: <Areca ARC-1210-VOL#00 R001> Fixed Direct Access SCSI-5 device
da0: 166.666MB/s transfers (83.333MHz DT, offset 32, 16bit)
da0: 305175MB (624999424 512 byte sectors: 255H 63S/T 38904C)
SMP: AP CPU #1 Launched!