SRX 5K Series with SPC3 card model will have the SPU running with memory allocated over 60% without any traffic on the device.
Memory utilization values can be seen running over 65% for the SPU even with no security flow sessions allocated or just a small number of sessions:
The below command will display the number of sessions per SPU and the CPU and Memory for CP and SPUs:
> show security monitoring Flow session Flow session CP session CP session FPC PIC CPU Mem current maximum current maximum 5 0 0 40 1 13107200 1 15728640 <<< CP running with 40% allocated memory 5 1 0 65 0 26214400 2 31457280 <<< SPU running with 65% allocated memory Total Sessions: 1 39321600 3 47185920
The behaviour is by design as the board has pre-allocated memory and will reach these 60-66% memory utilization values after boot up is completed;How to check the memory utilization:
> show security monitoring Flow session Flow session CP session CP session FPC PIC CPU Mem current maximum current maximum 5 0 0 40 1 13107200 1 15728640 <<< by default the CP will be around 40% 5 1 0 65 0 26214400 2 31457280 <<< by default the SPU will be around 65% Total Sessions: 1 39321600 3 47185920
Check the values from shell for the SPU:
>cli % vty fpc5.pic1 show memory ID Base Total(b) Free(b) Used(b) % Name -- ---------- ----------- ----------- ----------- --- ----------- 0 40000000 1073741824 780302912 293438912 27 Kernel 1 686620000 50358779904 4415876544 45942903360 91 User <<< Pre-allocated
The values of the SPC2 card are listed below, but it has a different design and should not be compared with SPC3 in terms of how memory is allocated
> show security monitoring Flow session Flow session CP session CP session FPC PIC CPU Mem current maximum current maximum 3 0 0 14 0 0 0 0 3 1 0 10 0 6291456 0 7549747 3 2 0 10 0 6291456 0 7549747 3 3 0 10 0 6291456 0 7549747