commit interval

[Thomas Andrews <tandrews grok co za>]

Hi,

I have an ext3 partition on a compact flash device. I was thinking of 
reducing the commit interval to say 30 sec, but I'm not sure it's really 
necessary.

What I'd like to know is if ext3 will *actually* do any writes to the 
journal if none of the data has changed, and given that it's mounted 
noatime. eg, if only one file is modified every hour, will the journal 
still write every 5 seconds?

I am using ordered mode btw.

Many thanks,
Thomas