noatime,nodiratime?

[Stan Hoeppner]

Need a little education here.  I have a general understanding of what the
inode access timestamps "are" but I have no idea what, if any, applications
make use of these access times.  I see posts all over Google land saying to
use "noatime,nodiratime,logbufs=8" for XFS mount options to increase
performance.

Is there any potential downside to disabling atime?  Do daemons such as
Dovecot or Samba need these access times updated?  Do any applications need
this?

Thanks.

-- 
Stan