RE: Filesystem Block Size ? 1K or 4K or 8K ?

From: Powell, Mark D <mark.powell_at_eds.com>
Date: Tue, 14 Oct 2008 10:15:10 -0400
Message-ID: <D1DC33E67722D54A93F05F702C99E2A902FC5CBE@usahm208.amer.corp.eds.com>

If the Oracle block size is 8K I see no valid reason why I would want an OS block size less than 8K. By having an 8K OS and Oracle block size one Oracle IO will equal one OS IO.  

• Mark D Powell -- Phone (313) 592-5148

  ---

        From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Zhu,Chao

	Sent: Tuesday, October 14, 2008 9:32 AM
	To: VIVEK_SHARMA
	Cc: ORACLE-L
	Subject: Re: Filesystem Block Size ? 1K or 4K or 8K ?
	
	
	Q1: I don't have performance test result about HP vxfs. But

vxfs_at_solaris using directio does not seems to make much difference per my past experience. And whether direct IO helps/how much it helps really depends on application profile. Same with Raw Devices. (more heavy write, more saving on CPU and better throughput.)

	      
	Q2: see metalink note 139272.1
	
	I don't see any benefit of using 1k/4k filesystem pagesize for a

8k db_block_size database. Won't consider that at all.                  

        On Tue, Oct 14, 2008 at 7:49 PM, VIVEK_SHARMA <VIVEK_SHARMA_at_infosys.com> wrote:                                            

---

                From: zhuchao_at_gmail.com [mailto:zhuchao_at_gmail.com]                                  

                If direct io is being used, the difference maybe less.

                Qs 1 -> What do you mean by "the difference maybe less."?                 

		Anyway I don't see any benefit using 1k/4k blocksize.
		If you want best throughput, go with raw volumes.

		
		Have done all tuning on hp kaio setup to maximize os

capability?

                Qs 2 -> Could you share some "tuning on hp kaio setup" please?                                   

---

                 

                HP who is partnering the Benchmark states - since Filesystems are being Mounted with Direct I/O therefore 1K F.S. block size is preferred to 8K.                                   

---

                From: zhuchao_at_gmail.com [mailto:zhuchao_at_gmail.com]

                Of course set to 8k                 

---

                We are in the process of Setting up DB Server for an OLTP Banking Application Benchchmark.                  

                HP-UX B.11.31

                system device block size(think this is the O.S. block size) = 1K

                Base page size = 4K.

                DB_block_size = 8K                  

                Should the Filesystem (VXFS) Block Size be set to 1K, 4K or 8K? ... Personally I think it should be 4 K (i.e. Equal to the Page-size)                  

• CAUTION - Disclaimer ***************** This e-mail contains PRIVILEGED AND CONFIDENTIAL INFORMATION intended solely for the use of the addressee(s). If you are not the intended recipient, please notify the sender by e-mail and delete the original message. Further, you are not to copy, disclose, or distribute this e-mail or its contents to any other person and any such actions are unlawful. This e-mail may contain viruses. Infosys has taken every reasonable precaution to minimize this risk, but is not liable for any damage you may sustain as a result of any virus in this e-mail. You should carry out your own virus checks before opening the e-mail or attachment. Infosys reserves the right to monitor and review the content of all messages sent to or from this e-mail address. Messages sent to or from this e-mail address may be stored on the Infosys e-mail system. ***INFOSYS******** End of Disclaimer ********INFOSYS***

	-- 
	Regards
	Zhu Chao
	www.cnoug.org
	
	

--
http://www.freelists.org/webpage/oracle-l

Received on Tue Oct 14 2008 - 09:15:10 CDT