On Mon, 25 Oct 2010, Jeff Lake - Admin wrote:
what I noticed first with this new system was a horrible lag in writing
the NEXRAD3 and LIGHTNING files to disk watching the incoming feed (
ldmadmin watch -f NEXRAD3) the file time and my receive time were the
expected 45sec to 90sec delay, but the write to disk was at least 4
minutes sometimes 6+ later ..
How are you dividing out the write tasks with LDM? Each pqact only has 32
pipes, so if you are attempting to fit too many products through those
available pipes, there will be lags.
Install system monitoring tools like 'dstat' and 'sysstat', monitor the
disk IO rates before you do something drastic like reformatting or
changing filesystems.
When I have seen problems before, it is almost always a LDM configuration
issue and not having enough pqacts running.
daryl
