Re: Storage imp log file.

Incase of 5.x hosts :

/var/log/vmkernel.log

/var/log/vmkwarning.log

/var/log/vobd.log

Incase of 4.x :

check /var/log/messages | grep -i vmkernel

Also verify with the command for the storage latency :

esxtop

ESXTOP - Yellow Bricks