Hi All ,
I got one reply back in regard to running diskx from
Dr. Alan Rollow , which is included below. I took his advice
and am vary happy with the read rate I am getting.
Can anyone tell me if the write rate I,ve got is normal ?
I have a 4100 with RZ29B disks.
It has a kzpsc-ba controller and is RAID 0 with
write through. Although my battery backups havent arrived
for the write back cache , I enabled and set it on and include
a diskx with the write back cache on.
Alan Rollow :
You're using the buffered device. The read rates are going to be
significantly affected by how much data is transferred and how
much of data stays in the cache. The write writes are affected
by the fact that the block device interface uses a constants
transfer size no matter what the program uses. I think the
size coming out the back of the cache is 2 KB. See if you get
more reasonable results using the character device.
diskx -f /dev/rre7b -p -n -S ( write through )
Part- Transfer Count of Read Write Transfer
ition Size Transfers Rate Rate Errors
--------------------------------------------------------------------------------
b 0.5 KB 262144 942.61 KB/sec 52.56 KB/sec 0
b 6.5 KB 20164 2.43 MB/sec 371.10 KB/sec 0
b 12.5 KB 10485 3.77 MB/sec 679.05 KB/sec 0
b 18.5 KB 7084 4.68 MB/sec 975.01 KB/sec 0
b 24.5 KB 5349 5.38 MB/sec 1.07 MB/sec 0
b 30.5 KB 4297 5.92 MB/sec 1.16 MB/sec 0
b 36.5 KB 3591 6.38 MB/sec 1.30 MB/sec 0
b 42.5 KB 3084 6.77 MB/sec 1.46 MB/sec 0
b 48.5 KB 2702 7.16 MB/sec 1.61 MB/sec 0
b 54.5 KB 2404 7.51 MB/sec 1.75 MB/sec 0
b 64.0 KB 2048 7.66 MB/sec 3.15 MB/sec 0
diskx -f /dev/rre7b -p -n -S ( Write back cache on )
Part- Transfer Count of Read Write Transfer
ition Size Transfers Rate Rate Errors
--------------------------------------------------------------------------------
b 0.5 KB 262144 917.13 KB/sec 638.98 KB/sec 0
b 6.5 KB 20164 2.43 MB/sec 1.36 MB/sec 0
b 12.5 KB 10485 3.75 MB/sec 1.99 MB/sec 0
b 18.5 KB 7084 4.66 MB/sec 2.36 MB/sec 0
b 24.5 KB 5349 5.35 MB/sec 2.57 MB/sec 0
b 30.5 KB 4297 5.88 MB/sec 2.60 MB/sec 0
b 36.5 KB 3591 6.34 MB/sec 2.94 MB/sec 0
b 42.5 KB 3084 6.63 MB/sec 2.97 MB/sec 0
b 48.5 KB 2702 7.04 MB/sec 3.23 MB/sec 0
b 54.5 KB 2404 7.35 MB/sec 3.57 MB/sec 0
b 64.0 KB 2048 7.49 MB/sec 13.24 MB/sec 0
Thanking you ,
Gary Menna E-Mail g.menna_at_isu.usyd.edu.au
Info Tech Services Phone +61 2 9351-6360
University of Sydney (G05) Fax +61 2 9351-7711
************************************************************************
We all enter this world in the same way: naked, screaming, and soaked in
blood. But if you live your life right, that kind of thing doesn't have
to stop there. -- Dana Gould
************************************************************************
Received on Tue Jul 08 1997 - 03:41:31 NZST