[Novalug] ext3 and noatime

[Richard Rognlie]

On Sun, Feb 03, 2008 at 11:19:19AM -0500, Miguel Gonzalez Castaños wrote:
> Hi,
> 
>  I'm researching on how to tune ext3 filesystems in Virtual machines 
> using iSCSI. I have checked the performance of the raw disk is good 
> (around 90-100 MB/s) but the performance of the underlying filesystem is 
> low (around 16 MB/s).
> 
>  This guy claims that mounting the filesystem with noatime improves the 
> performance:
> 
>  http://ubuntuforums.org/showthread.php?t=107856
> 
>  I've checked it together with nodiratime and writes boosted to 85 MB/s 
> which is pretty similar to the raw disk performance.
> 
>  The guy in blog says that could lead to some problems using make but 
> he hasn't experienced anything similar, does anyone know if this noatime 
> settings could cause any data corruption or any problem? We are going to 
> use it probably for Subversion repositories and maybe Apache websites.

noatime should not impact make and similar utilities, since they only
really care about "mtime" not "atime".  I know of no utilities that 
rely on atime for anything useful.  Any useful caching utilities
might, but for the most part, you'd be using the cache itself for read
not the underlying disk.

net-net... go for it.  In 15 years of unix development, I've never 
seen "noatime" cause an issue.


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