NFS asynchronous Vs. synchronous writes

[Shailendran V Naidu]

Thats some research ......
biod is supposed to be the NFS client deamon, can you mount NFS shares with no biods running !? Never heard of it.

Anyone can post more details ?

[Dave Olker]

Biods are an *optional* daemon for the NFS client. If they are running they will handle the asynchronous read and write requests on the applications' behalf. If there are no biods running then the reading or writing application will perform these over-the-wire calls in its own process context.

Try it for yourself. Terminate all the biods and see if you can still access/read/write to your NFS filesystems.

In the vast majority of cases biods are helpful to application performance. There have been very few cases in the past where specific application workloads would run faster with no biods on the system. One major underlying cause was a "thundering herd" condition in the biod code that we've since identified and resolve (the fix is in the latest patches and using the kctune parameter set I described in a previous post in this thread).

Again, biods are optional, not required. Easy enough to prove by terminating them. However, in nearly every situation you'll get better performance with them than without them.

All of this is specific to 11i v2 and prior, since 11i v3 doesn't use biods.

Let me know if you have any other questions about this.

Regards,

Dave