We have 3 DX-3600 appliances running in active/active mode and we might need a 4th incase one appliance goes down. I am trying to find out the amount of free resources during our peak usage, but when I run show capacity and show vmstat I am getting two different results. The cpu usage on show capacity is the amount of cpu being used and the cpu usage on show vmstat "n" is the amount idle, but even taking this into consideration they are still showing different results.
The 'show capacity' command shows values based off an average from the vmstat output:
CPU - show % in use by userland and system (average over the last 60 seconds.). Memory - Amount of free memory in the system (average over the last 60 seconds). Network - show bytes in per second for interface ether0 and ether1 (average over the last 60 seconds).
So these displayed values are an average over the last minute and the sample interval is one second. This allows smoothing of the peaks in the values, as previously using just vmstat output intermittent CPU spikes would cause the DX to report the CPU usage as "red" for a brief period. There is a CLI command "set server factory a ssw" to change the (default) average period to less than 60 seconds.