[CentOS] Drive activity every 30sec

Florin Andrei florin at andrei.myip.org
Mon Jul 7 23:51:59 UTC 2008

Robert Moskowitz wrote:
>> I'm sure there are other things as well but first thing comes to mind is
>> disabling atime for your file systems, to test the change you can do this
>> (for each of the mount points)
>> mount <mount point> -o remount,noatime
> Everything is quite on the notebook front. Now.
> But What is going on here?

It's an old Ext2/3 feature that updates the atime information every time 
a file is accessed, even when the file is just being read from, not 
written to, thereby transforming even read-only disk operations to 
read-write. It's useless in pretty much every situation, except if you 
need to do disk forensics (there's a break in and you need to figure out 
everything that the attacker did to your system).

There were talks on LKML a while ago to change the default from atime to 
noatime. I don't know what was the result of that.

Bottom line: disable atime on all systems unless you _really_ need to do 
disk forensics. You will see a performance improvement in almost every 

Florin Andrei


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