First thing I would look at is CPU. You have to be able to feed the beast.
Does the z/OS system have more MIPS available?
When you say Ave. 25 MB/s, how is that measured?
With DDR are not compressing the data before sending it to the channel and are
you allowing FDR to compress the data?
What I'm getting at, is perhaps both are transmitting over the channel at 25
MB/s.
The DDR, perhaps, not compressed. So you are getting 25MB/s off the disk also.
And then the FDR may be doing compression, so you're getting 75 MB/s off of
disk, but only transmitting 25 MB/s over the channel.
Could FDR be doing better I/O overlap than DDR? Perhaps doing much better at
buffering?
A lot of this is apples to oranges. We need to get to a common fruit <G>.
Tom Duerbusch
THD Consulting
>>> "Frank M. Ramaekers" <framaek...@ailife.com> 9/30/2009 2:28 PM >>>
We have two z9 systems attached attached to a 3584 library.
System 1 - z/VM 5.4 with (7 z/VSE 4+ guests)
System 2 - z/OS 1.9
System 1 Test 1 - z/VM DDR Avg. 25MB/s
Test 2 - z/VSE FASTCOPY Avg. 24MB/s
System 2 Test 1 - z/OS FDR Avg. 75MB/s
- z/OS FDR 2drvs Avg. 63MB/s
I don't quite understand why the VM/VSE (System 1) can only get about
1/3 the data rate of the z/OS system.
Thoughts?
Frank M. Ramaekers Jr.
Systems Programmer MCP, MCP+I, MCSE & RHCE
American Income Life Insurance Co. Phone: (254)761-6649
1200 Wooded Acres Dr. Fax: (254)741-5777
Waco, Texas 76710
_____________________________________________________
This message contains information which is privileged and confidential and is
solely for the use of the
intended recipient. If you are not the intended recipient, be aware that any
review, disclosure,
copying, distribution, or use of the contents of this message is strictly
prohibited. If you have
received this in error, please destroy it immediately and notify us at
privacy...@ailife.com.
