Chris Smith wrote:
What build/version of Solaris/ZFS are you using?
Solaris 11/06.
What block size are you using for writes in bonnie++?
I
ind performance on streaming writes is better w/
larger writes.
I'm afraid I don't know what block size bonnie++ uses by default - I'm not
specifying one on the commandline.
trussing bonnie will tell you... I just built bonnie++; by default it
uses 8k.
What happens when you run two threads at once? Does
write performance
improve?
If I use raidz, no (overall throughput is actually nearly halved !). If I use
"RAID0" (just striped disks, no redundancy) it improves (significantly in some
cases).
Increasing the blocksize will help. You can do that on bonnie++ like
this:
./bonnie++ -d /internal/ -s 8g:128k ...
Make sure you don't have compression on....
Some observations:
* This machine only has 32 bit CPUs. Could that be limiting performance ?
It will, but it shouldn't be too awful here. You can lower kernelbase
to let the kernel have more of the RAM on the machine. You're more
likely going to run into problems w/ the front side bus; my experience
w/ older Xeons is that one CPU could easily saturate the FSB; using the
other would just make things worse. You should not be running into that
yet, either, though. Offline one of the CPUs w/ psradm -f 1; reenable
w/ psradm -n 1.
* A single drive will hit ~60MB/s read and write. Since these are only 7200rpm
SATA disks, that's probably all they've got to give.
On a good day on the right part of the drive... slowest to fastest
sectors can be 2:1 in performance...
What can you get with your drives w/ dd to the raw device when not part
of a pool?
Eg /bin/ptime dd if=/dev/zero of=/dev/dsk/... bs=128k bc=20000
You can also do this test to a file to see what the peak is going to be...
What kind of write performance do people get out of those honkin' big x4500s ?
~2GB/sec locally, 1 GB/sec over the network.
This requires multiple writing threads; a single CPU just isn't fast
enough to write 2GB/sec.
- Bart
--
Bart Smaalders Solaris Kernel Performance
[EMAIL PROTECTED] http://blogs.sun.com/barts
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