Unanswered: How to set up max IO size on RHEL 4.0 ?
platform is RHEL 4.0.
Description of the issue: With RH AS 2.1,
it was advised to set up fs.aio-max-size up to 1048576 to speed up 'create database' statement.
With RH AS 4.0, setting up this key is not allowed?
I get following output when trying to set it:
I'm not system engineer , I might be wrong, I only hope this help you in your investigations.
Seems that fs.aio-max-size is used when Asynchronous I/O is set:
What about your kernel version ?
According quick search I make on internet it seems that Asynchronous I/O can be used on RAWIO, EXT2, EXT3, REISERFS filesystem and is not supported on NFS.
Does your kernel support one of these FS ?
I heard about a Async I/O library as well: libaio. Not sure it exists or not in your redhat box.
Might be possible for you to recompile the kernel...
This kernel parameter doesn't exist in the 2.6.x kernel as those performance improvements have been integrated into the standard device drivers and are based on the physical capabilities of the HBA drivers (maximum number of concurrent 4K blocks that the driver can handle, IIRC).
BTW - I found this information by a quick google search on fs.aio-max-size and 2.6 :-)