Hello,
I have a 2100A with single 5/250 CPU and 2 KZPSCs - 3 port raid. Used
LSM to mirror root, swap, and user, and 2 more partitions on the 2
internal drives with no problems! (OS is 3.2F)
Then I used LSM to create a raw prtition using 3 re raid 5 volumes -
WBC enabled - over the 2 controllers. When using dd to write or
read from the /dev/rvol... I got very poor numbers - only about
500K/sec with very low I/O rate! I tried differant LSM stripe width,
with no effect on performance! I then broke up the volume, and tested
throughput to /dev/rre0g - I got a write rate of about 9MB/sec and I/O
rate of about 600I/Os /sec.
I then create the volume again using LSM, and tried with Sybase -
initialization of the 24GB to tablespace took only 8 minutes! After
loading the DB, I tried a count(*) operation on a non index field -
should do a full table scan - monitored I/Os, and only saw about
30 I/Os /sec - total throughput about 500K/sec once in a while
will shoot up to 4MB/sec for a short time - It seems like LSM causing
a major botleneck - I axpected some, but not that bad!
The performace was the same when used only 2 re volumes, 1 per
controller.
The volassist command:
volassist -U gen make data-vol 24g layout=stripe nstripe=3 \
stripe_width=128 re0 re8 re9
voledit set user=sybase mode=0600 data-vol
Thank alot for your time!
Ohad
Received on Fri Aug 02 1996 - 22:49:32 NZST