RE: I/O and db_file_multiblock_read

From: Kevin Closson <kevinc_at_polyserve.com>
Date: Thu, 14 Dec 2006 10:37:20 -0800
Message-ID: <5D2570CAFC98974F9B6A759D1C74BAD001C337CF@ex2.ms.polyserve.com>

oh man...how weird... a double-inverted-typo-entendre!

[root_at_tmr6s14 u03]# time dd if=f1 of=/dev/zero bs=1024k
1024+0 records in
1024+0 records out

real 0m12.350s
user 0m0.001s
sys 0m0.226s
[root_at_tmr6s14 u03]# time dd if=f1 of=/dev/null bs=1024k
1024+0 records in
1024+0 records out

real 0m12.381s
user 0m0.001s
sys 0m0.272s

	From: Jesse, Rich [mailto:Rich.Jesse_at_qg.com] 
	Sent: Thursday, December 14, 2006 10:26 AM
	To: kevinc_at_polyserve.com
	Subject: RE: I/O and db_file_multiblock_read_count
	
	
	Hey Kevin,
	 
	I wouldn't have thought of it either.  I blatantly plagarized

the methods of the List Experts:

http://www.freelists.org/archives/oracle-l/12-2006/msg00351.html

Perhaps it was your clone? ;)

Rich

From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Kevin Closson

	Sent: Tuesday, December 12, 2006 11:35 AM
	To: oracle-l
	Subject: RE: I/O and db_file_multiblock_read_count
	
	
	I would have never though a write to /dev/zero would work...I
learn something new every day.
	Can you try this test writing to /dev/null?


________________________________

		From: Jesse, Rich [mailto:Rich.Jesse_at_qg.com] 
		Sent: Tuesday, December 12, 2006 7:16 AM
		To: kevinc_at_polyserve.com; oracle-l
		Subject: RE: I/O and db_file_multiblock_read_count
		
		
		I'm guessing that I'm limited by CPU on this IBM JS21

blade's LPAR (MPV, 2 cores max) with an SVC (virtualized SAN) backend. topas showed kernel mode CPU >95% for most of the tests.

		/oracle $ time dd if=S.dbf of=/dev/zero bs=1024k
		16384+1 records in
		16384+1 records out
		 
		real    1m3.044s
		user    0m0.271s
		sys     0m42.458s
		
		/oracle $ time dd if=S.dbf of=/dev/zero bs=1024k
		16384+1 records in

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Received on Thu Dec 14 2006 - 12:37:20 CST