OT - more about iometer and AIO

[guy keren]

This goes to dan, but will interest anyone else trying to use iometer on 
linux (i.e. running 'dynamo' on linux).

on some linux distributions (e.g. on centos), the 'rt' library has an 
implementatoin of aio_read/aio_write that simulates AIO using 
synchronous I/O - instead of using the real AIO interface on linux.

on centos 5.X - you need to link with '-lrtkaio' instead of '-lrt' when 
compiling the 'dynamo' part of iometer.

in order to know if your dynamo is using AIO or not - you need to run 
it, cause it to perform I/O, find its process id, and then
run 'strace -eio_submit -p <process id>' and look at the output.
  if you get no output - the process is not using AIO. if you get output 
- it is using AIO.

dan - if you could make this strace test on your fedora system and let 
me know the results - that'll be great. i want to find a clear way to 
find the real library that should be linked to - and then send a patch 
to the iometer developers (who all seem to be too much windows-oriented).

thanks,
--guy