[ltp] HDD access avery 5 seconds?

Richard Neill linux-thinkpad@linux-thinkpad.org
Thu, 14 Aug 2008 16:12:18 +0100


Kiko Piris wrote:
> On 14/08/2008 at 15:15 +0100, Richard Neill wrote:
> 
>> Thanks - that's very useful. Just one thing puzzles me: why would ext3  
>> flush the journal at all if the machine is idle; if no files have been  
>> modified during that period, surely there's no data, nor updates to the  
>> journal to be saved to disk?
> 
> Mounting filesystems with noatime and nodiratime is crucial.
> 
> If not, that means that every file read becomes also a write (filesystem
> needs to update atimes).
>

I've already go noatime everywhere.
Do I need nodiratime too, or is nodiratime a subset of noatime?
[Also, I just tried remounting everything with nodiratime, and it 
doesn't fix this issue].

However, that isn't really the root cause. What I want to know is:
How do I identify which *process* is accessing the filesystem (and 
thereby causing disk access) when the machine is idle.

Presumably something must be making changes to the files? Or would, for 
example, sync cause disk activity even when there is nothing that needs 
to be flushed?

Richard