Before setting up Red Hat GFS2, make sure that you have noted the key characteristics of the GFS2 nodes (refer to Section 1.2, “Before Setting Up GFS2”). Also, make sure that the clocks on the GFS2 nodes are synchronized. It is recommended that you use the Network Time Protocol (NTP) software provided with your Red Hat Enterprise Linux distribution.
The system clocks in GFS2 nodes must be within a few minutes of each other to prevent unnecessary inode time-stamp updating. Unnecessary inode time-stamp updating severely impacts cluster performance.