[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
scenario.
--
Florin Andrei
http://florin.myip.org/
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