Re: AIX concurrent I/O in database environments
From: Wilfrid Allembrand (wilfrid.allembrand_at_gmail.com)
Date: 13 Jul 2005 09:12:12 -0700
I also configured CIO on my P570 box, AIX 5.2 ML6, Oracle 9iR2. Nice
improvements (about 20%).
Also noticed that it's slow when restoring big files onto FS with CIO.
Noticed too that you must be carefull with AIX patches : CIO and JFS2
is not yet completly mature and you can get JFS2 FS corruption which,
of course, can corrupt your datafiles (that's what I got so I had to
apply a recent patch from mid june)...
Just my 2 cents.
email@example.com a écrit :
> firstname.lastname@example.org wrote:
> > DIO doesn't work on jfs2, it's for jfs.
> Uh.... wrong. DIO works with JFS2. Did you read the article
> via the link I provided? A good full 3 pages on how DIO works
> with JFS2.
> In fact CIO is actually DIO with the Inode lock acquired in read-shared
> mode for both reads and writes.
> JFS2 uses a read-shared, write-exclusive inode lock, so when a write
> occurs, the file system is locked for both reads and writes.
> Under CIO the inode lock is acquired in read-shared mode for both read
> and write access, in most cases.