Rob Kampen wrote:
I do not agree - every read of the db will update the filesystem with noatime missing, thus specifying noatime does give performance improvements - the size of the files does not matter as much - rather the number of reads vs writes.
Interesting, didn't think about that aspect, I dug around and at least for MySQL and Postgresql noatime doesn't appear to provide any noticeable benefit(it may be a measurable one in some cases)
http://www.mysqlperformanceblog.com/2007/11/01/innodb-performance-optimizati...
http://www.ffnn.nl/pages/articles/linux/server-wide-performance-benchmarking...
If your doing a ton of reads and only have a few files, it's likely there isn't going to be many atime updates as the file is kept open for an extended period of time(e.g. scanning a table with 100k rows).
For DB performance there's a lot more useful areas to spend time tuning. As DBAs often say you can get 10% more performance tuning the OS and getting better hardware, and you can get 1000% better performance by tuning the queries and data structures, or something like that :)
nate