[Ocfs-users] RHEL 3 and OCFS 1.0.9-12 / 1.0.11-1

Baqir Hussain bhussain at ZipRealty.com
Wed Mar 24 11:46:50 CST 2004

Is the following statement still valid for either OCFS 1.0.9-12 or OCFS
The following is from one of the questions put forward by Derek Suzuki on
"A couple more minor questions about OCFS and RHEL3"

> Next, I saw a Metalink thread which suggests that async I/O is not >
supported on OCFS with RHAS 2.1. It doesn't say anything about RHEL3. >
We've been using async in our testing with no problems so far, and plan to >
use it in production unless Oracle feels the combination is not yet >

well - tough one, it works, but the big issue is that you rredologfile need
to be contiguous on disk, otherwise you might have failures, exact same goes
for rhel3 as rhas21.
 you can see that by running debugocfs 
eg : /ocfs/log/foo1.dbf -> debugocfs -f /log/foo1.dbf /dev/sdXXX that will
show how many offsets (should only have one) in the extents if its more than
1, dd it over with a very large blocksize and see if that ends up being 1
contig file. if you do that, everything should work, however, there just
hasn't been enough real testing with aio, need to ggather more evidence. the
reason the logfiles are annoying is because he way aio is implemented and
how we call it, it cannto handle short io's or non contig aio submits. 

Baqir Hussain
Database Administrator
zipRealty Inc.

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