On Tuesday 29 June 2004 20:33, [EMAIL PROTECTED] wrote: > ==> In article <[EMAIL PROTECTED]>, Joni Moyer <[EMAIL PROTECTED]> writes: > > Hello all! > > > > I was reading the performance tuning guide and it states that we should > > use raw partitions for server db, log and disk storage pool volumes for > > an AIX server and I was just wondering if this is true and what the > > benefits are of configuring volumes in this manner? > > Simpler, faster, less space overhead. Euh, yes and no. For AIX and jfs2 file systems, you can enable CIO (in /etc/filesystems: "options = rw,cio"). If you do so, your file systems are as fast as raw devices. So you have the benefits of a file system and the speed of a raw device. The I/O requests are directly done on the disk, all cache is skipped. I have a pdf file about this setup for oracle and the speed you can get. We once enabled this on a very busy AIX server and the oracle database was very, very fast.
> > As I understand it, if we configure raw logical volumes, the AIX volume > > group will need to be applied to a raw logical volume, as opposed to a > > standard UNIX filesytem. For each disk and logical volume, there is a /dev/r* device that you can use. This is the raw device version of the normal /dev/* device. Stef -- [EMAIL PROTECTED] "Using Linux as bandwidth manager" http://www.docum.org/
