Hp-UX "maxiosize" for Oracle DBAs?

[Stuart Abramson_2]

Our DBAs are getting some Oracle error "ora-3232".

They have asked me what is our "max io size?"

I have no idea what they mean. It's like I'm speaking English and they're speaking Greek. (or vice-versa).

Then they ask "what is our i/o block size?", and I say that there is a parameter on "newfs" called block size "-b" and we default to 1024 bytes. Then they ask why does "du" report file-system size in blocks of 512?

Does anyone know to what they refer? Or how I can help them?

In a previous place we set all "newfs -b 8192" because the Oracle DBAs had set their Oracle block size to 8 MB.

[Todd McDaniel_1]

Stuart,

By default du reports in 512... you can report it in 1024 by using the -k option...

Your I/o block size I think they are referring to the extent size or if you have striping, they are probably referring to your stripe size...

Either way you can use lvdisplay to view it...

[Pete Randall]

Stuart,

You might be interested in this currently ongoing thread:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=372950


Pete

[A. Clay Stephenson]

The answer depends upon the OS and it ranges (off the top of my head) from 256KB to 1MB but it really doesn't matter nor does filesystem blocksize matter --- despite what has been beaten into their DBA heads by Oracle.

Vxfs filesystems are extent-based rather than block-based. Filesystem block size has no impact upon the i/o performance in a vxfs filesystem although it is very significant in an hfs filesystem. You shouldn't be using hfs in any event because vxfs performance has far outstripped hfs for several years.

A pretty good all-around Oracle block size is 8KB although some perform significantly better at 16K or 32K but I would suggest 8KB as a very-good compromise.

[Todd McDaniel_1 · Accepted solution]

Here are a few links regarding the error... Just search the article for the keyworkd ora-3232...

http://docs.linux.cz/Oracle8/readme.htm

http://databasejournal.com/features/oracle/article.php/10893_3068711_2

ON this next one look at page 43 in the pdf...http://otn.oracle.com/products/designer/pdf/9i-1_migration-guide.pdf

[Florian Heigl (new acc)]

ORA-3232: unable to allocate an extent of %s blocks from tablespaces %s

- I have seen this one some day, too.
Either a full tablespace or a fragmented one.

[Stuart Abramson_2]

Thanks, Todd. In actuality they have an Oracle problem which doesn't have anything to do with HP-UX blocks, block-sizes or i/o configuration.