Re: blocksize on AIX
Hi, blocksize in aix is 4k by default, not 512 byte. And read ahead can be controlled by aix kernel parameter. If you really want to bypass aix filesystem read ahead, just change the kernel parameter dynamically. (I cannot remember the detailed kernel parameter, maybe min/maxpgahead)). Oracle document says db_block_size should be multiple of os_block_size, not db_block_size should be the same as os_block_size. Zhu Chao. www.cnoug.org. - Original Message - To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED] Sent: Friday, October 03, 2003 3:14 AM We use 8192 on AIX and have no problems. The AIX block size is 512 so I know it is advisable to have a multiple of 512, other than that I know of no other caveat. Ruth -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Hans de Git Sent: Wednesday, October 01, 2003 4:24 AM To: Multiple recipients of list ORACLE-L Subject: blocksize on AIX Hi all, I've read on ixora.com.au and other sites that the optimal block size for AIX is 4K, because JFS pages are 4K also. Has anyone of you ever experienced performance problems on AIX due to a larger blocksize? What exactly are the 'read ahead' issues and cpu problems regarding double buffering etc. Are there any alternatives, other than moving to raw volumes? HTH, Hans _ MSN Zoeken, voor duidelijke zoekresultaten! http://search.msn.nl -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Hans de Git INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Ruth Gramolini INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: zhu chao INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
RE: blocksize on AIX
We use 8192 on AIX and have no problems. The AIX block size is 512 so I know it is advisable to have a multiple of 512, other than that I know of no other caveat. Ruth -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Hans de Git Sent: Wednesday, October 01, 2003 4:24 AM To: Multiple recipients of list ORACLE-L Subject: blocksize on AIX Hi all, I've read on ixora.com.au and other sites that the optimal block size for AIX is 4K, because JFS pages are 4K also. Has anyone of you ever experienced performance problems on AIX due to a larger blocksize? What exactly are the 'read ahead' issues and cpu problems regarding double buffering etc. Are there any alternatives, other than moving to raw volumes? HTH, Hans _ MSN Zoeken, voor duidelijke zoekresultaten! http://search.msn.nl -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Hans de Git INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Ruth Gramolini INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
blocksize on AIX
Hi all, I've read on ixora.com.au and other sites that the optimal block size for AIX is 4K, because JFS pages are 4K also. Has anyone of you ever experienced performance problems on AIX due to a larger blocksize? What exactly are the 'read ahead' issues and cpu problems regarding double buffering etc. Are there any alternatives, other than moving to raw volumes? HTH, Hans _ MSN Zoeken, voor duidelijke zoekresultaten! http://search.msn.nl -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Hans de Git INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
Re: blocksize on AIX
I've read on ixora.com.au and other sites that the optimal block size for AIX is 4K, because JFS pages are 4K also. Isn't JFS block size changeable? Has anyone of you ever experienced performance problems on AIX due to a larger blocksize? What exactly are the 'read ahead' issues and cpu problems regarding double buffering etc. Are there any alternatives, other than moving to raw volumes? I think read ahead problems on 4k file system with 8k block size might mean that some operating systems will do readahead caching when they see more than one consecutive block requested from file system. So, every oracle single-block read will actually result in much larger read by OS. This isn't that bad when Oracle itself is doing big multiblock reads, but for single block reads it might cause performance problems. Tanel. HTH, Hans _ MSN Zoeken, voor duidelijke zoekresultaten! http://search.msn.nl -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Hans de Git INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Tanel Poder INET: [EMAIL PROTECTED] Fat City Network Services-- 858-538-5051 http://www.fatcity.com San Diego, California-- Mailing list and web hosting services - To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
