VXFS Discovered Direct I/O

[Mitch Mohlman]

Does HP's port of Veritas vxfs support Discovered Direct I/O? If not, why/when? If so, then where can I find supporting documentation?

I am also interested in finding an HP port of vxbench.

The attachment is a 1996 whitepaper I found on VERITAS's web site.

[Gadura Praveen]

Hello Mitch,

HP has started porting the "vxtunefs" command with the Base VXFS Filesystem ( JFS B.11.11 ) on HPUX 11.11 . The man page lists the feature "discovered_direct_io" along with other features which can be used on VXFS filesystems.If , you do not have a 11.11 system , you can read the man page at:-
http://docs.hp.com/hpux/onlinedocs/B2355-90692/00/02/233-con.html

I have not seen the vxbench ( or equivalent ) on my 10.20/11.00 or 11.11 servers.

Hope this helps.

[Mitch Mohlman]

Gadura, Thanks for the reply. No we don't have any 11.11 systems yet. I will read up on the vxfs changes coming with 11.11.

FYI, read thru the WP I attached. You will see why I am interested in Discovered Direct IO. Thanks again. -Mitch

[Gadura Praveen · Accepted solution]

Hi Mitch,

It sure sounds interesting. As of pre-11.11 releases we are just using the direct I/O for Oracle database ( using mincache and convosync mount options). Thanks for the points.

[David Snider]

We are using the OnlineJFS 3.3 product on 11.00. This purchaseable product comes with the vxtunefs command and support for discovered_direct_io.. Currently we are also using mincache=direct, convosync=direct mount options for our Oracle DB's, we did a little playing with discovered_direct_io and saw no improvement over our current mount options. However, according to the documentation, there are many other benefits to the online JFS vxtunefs product if you are utilizing striped sets through lvm... We are implementing an EMC 3430 later next week, so, we'll be playing with that feature then.. ;-)