On Sat, 26 Aug 2006, Jeff Ross wrote:
I followed with great interest the recent thread on misc@
http://marc.theaimsgroup.com/?l=openbsd-misc&m=115620585301672&w=2
aboout bad write performance with the MegaRAID 320-2 card, since I was also
experiencing what I perceived to be slow write performance with the same
card.
Unlike Robert Urban, my set up is three sets of RAID 1 drives, using Hitachi
10K disks. (dmesg follows).
Here are the results of a couple of tests that I ran with an LSI MegaRAID
320-2X with and without an onboard battery. I'd love to figure out why I got
no significant change with or without a battery.
bsd.mp with battery installed but not connected, write through, adaptive
read, direct I/O:
[EMAIL PROTECTED]:/home/jross $ dd if=/dev/zero of=/backup/test_file bs=64k
count=102400
102400+0 records in
102400+0 records out
6710886400 bytes transferred in 130.387 secs (51468680 bytes/sec)
bsd.mp with battery installed and connected, write back, adaptive read,
direct I/O:
[EMAIL PROTECTED]:/home/jross $ dd if=/dev/zero of=/backup/test_file bs=64k
count=102400
102400+0 records in
102400+0 records out
6710886400 bytes transferred in 132.209 secs (50759331 bytes/sec)
dmesg:
<snipped>
This is not a goood benchmark. Here seems to be a better one:
dukkha and nirvana are virtually identical servers, both running the same
kernel. dukkha's battery unit for its LSI card hasn't been installed yet.
Here is dukkha doing its altroot thing with no battery backup on the LSI
card:
OpenBSD 4.0-beta (GENERIC.MP) #20: Thu Aug 24 17:08:00 MDT 2006
[EMAIL PROTECTED]:/usr/src/sys/arch/i386/compile/GENERIC.MP
9:19AM up 2 days, 18:24, 5 users, load averages: 0.18, 0.19, 0.16
Removing scratch and junk files:
Backing up root filesystem:
copying /dev/rsd0a to /dev/rsd1f
31995+1 records in
31995+1 records out
262103552 bytes transferred in 33.298 secs (7871297 bytes/sec)
** /dev/rsd1f
** Last Mounted on /
And here is nirvana doing the altroot thing with the battery backup on the
card:
OpenBSD 4.0-beta (GENERIC.MP) #17: Thu Aug 24 16:48:07 MDT 2006
[EMAIL PROTECTED]:/usr/src/sys/arch/i386/compile/GENERIC.MP
9:29AM up 1 day, 15:47, 4 users, load averages: 3.12, 2.88, 2.67
Removing scratch and junk files:
Backing up root filesystem:
copying /dev/rsd0a to /dev/rsd1g
31995+1 records in
31995+1 records out
262103552 bytes transferred in 11.636 secs (22524909 bytes/sec)
** /dev/rsd1g
** Last Mounted on /
Or, on the order of three freaking times faster!
The last dd test I tried was from /dev/zero to the raw device, so when
done I had to newfs the partition and was shocked to see newfs fly by,
where before it was very slow.
So, the short version is that the battery backup does make a BIG
difference.
--
Jeff Ross
