You're probably hitting a device/controller contention problem. Try multiple devices on multiple arrays with a striped logical volume.
On Tue, 2003-12-09 at 12:14, Jason Herne wrote: > I think we may have a performance problem. > > Our z/800 model 0LF is connected to an ESS800 with two Ficon channel > paths. We have been running dbench in Linux for quite a few weeks now > and we are seeing numbers much lower than we expected. Can someone > commnet on this? Are these numbers about what we should be seeing, or > is something wrong with our setup? > > We're running RHEL with kernel 2.4.21-1.1931.2.399.ent #1 SMP. Linux is > using a single 3390 DASD with ext3. > > Here are the numbers we're getting: > all tests were run on a single guest with no other Linux guests and just > a few z/VM service guests running. No disk intestive or CPU intensive > workload was running during the testing. > > dbench clients avg throughout (MB/s) > 1 123.111 > 3 116.729 > 6 99.0626 > 9 95.3577 > 12 95.2825 > 15 91.6009 > 18 92.7745 > 21 91.8808 > 24 73.8885 > > > Here is what we get with our $1000 Dell Pentiium 2.4Ghz server with a > SCSI disk. > > 1 395.545 > 3 281.957 > 6 275.292 > 9 285.756 > 12 262.4333 > 15 248.314 > 18 237.879 > 21 221.74355 > 24 200.873 > > > As you can see, the $1k Dell is hammering our $250k mainframe. We are > currently trying to figure out why this is and hopefully fix the problem > if there is indeed a problem... Any comments or help that anyone could > give woule be appreciated. > > - Jason Herne ([EMAIL PROTECTED]) > Clarkson University Open Source Institute > z/Server Administrator -- Rich Smrcina Sr. Systems Engineer Sytek Services - A Division of DSG Milwaukee, WI rsmrcina at wi.rr.com rsmrcina at dsgroup.com Catch the WAVV! Stay for requirements and the free-for-all. Update your zSeries skills in 4 days for a very reasonable price. WAVV 2004 in Chattanooga, TN April 30-May 4, 2004 For details see http://www.wavv.org
