The atime and noatime attribute Linux records information about when files were created and last modified as well as when it was last accessed. There is a cost associated with recording the last access time. The ext2 file system of Linux has an attribute that allows the super-user to mark individual files such that their last access time is not recorded. This may lead to significant performance improvements on often accessed frequently changing files such as the contents of the /var/spool/news directory. Linux has a special mount option for file systems called noatime that can be added to each line that addresses one file system in the /etc/fstab file. If a file system has been mounted with this option, reading accesses to the file system will no longer result in an update to the atime information associated with the file like we have explained above. The importance of the noatime setting is that it eliminates the need by the system to make writes to the file system for files which are simply being read. Since writes can be somewhat expensive, this can result in measurable performance gains. Note that the write time information to a file will continue to be updated anytime the file is written to. In our example below, we will set the noatime option to our /chroot file system. source : http://tldp.org/LDP/solrhe/Securing-Optimizing-Linux-RH-Edition-v1.3/chap6sec73.html
$lsattr yt-chanrip ------------------- yt-chanrip $ls -l yt-chanrip -rw-r--r-- 1 jeffrin jeffrin 230 Sep 2 18:19 yt-chanrip $chattr +A yt-chanrip $lsattr yt-chanrip -------A----------- yt-chanrip $ls -l yt-chanrip -rw-r--r-- 1 jeffrin jeffrin 230 Sep 2 18:19 yt-chanrip $echo " " >> yt-chanrip $lsattr yt-chanrip -------A----------- yt-chanrip $ls -l yt-chanrip -rw-r--r-- 1 jeffrin jeffrin 234 Nov 29 22:30 yt-chanrip $time real 0m0.000s user 0m0.000s sys 0m0.000s $chattr -A yt-chanrip $echo " " >> yt-chanrip $ls -l yt-chanrip -rw-r--r-- 1 jeffrin jeffrin 238 Nov 29 22:31 yt-chanrip $