Date, System Uptime and Clock:
Confirm the correct date is set on the system using the 'date' command.
The system uptime can be examined using the command:
09:46:34 up 124 days, 9:40, 1 user, load average: 0.36, 0.19, 0.14
If a low uptime is shown it normally indicates that the firewall has been administratively rebooted but it may also have been due to a self-reboot, for example due to a panic.
Low uptime - if you suspect the uptime is less than it should be check the
/var/log/messages file for the reason of the last reboot.
The disk space usage can be examined using the command:
[Expert@Zulu]# df –k
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda5 600832 187800 382512 33% /
none 600832 187800 382512 33% /dev/pts
/dev/sda1 147766 10124 130013 8% /boot
/dev/sda7 1541680 930324 533044 64% /opt
none 2045688 0 2045688 0% /dev/shm
/dev/sda6 1541680 593844 869524 41% /sysimg
/dev/sda8 27024000 5472984 20178264 22% /var
In the above example, all partitions are under 70% usage.
If a partition has a „use%' that is more than 70% but less than 90%
If the „use%' is 90% or more
See if the partition can be cleaned up to free up disk space.
/var/opt/CPsuite-RXX/fw1/log may be filled with old log files if the firewall has been logging locally.
/var/log may have old messages files
Physical RAM and Swap Space:
Examine the RAM and swap space usage (kilobytes) with:
free –k –t
[Expert@Zulu]# free –k -t
total used free shared buffers
Mem: 2058236 971332 1086904 0 95104
-/+ buffers/cache: 607244 1450992
Swap: 4192944 0 4192944
Total: 6251180 971332 5279848 [Expert@Zulu]#
The „total‟ column shows the amount of RAM installed in the system (2GB in the above example)
and the amount of disk space allocated for swap space (4GB).
The amount of swap space is normally automatically set to twice the size of the physical memory, with 4 GB being the maximum.
The „used‟ column indicates how much RAM and swap space are being used.
The „free‟ column indicates how much RAM and swap space are available.
In the above example output the „used‟ column indicates <1 GB of RAM is being used and no
swap space is being used.
If for some reason the amount of free RAM becomes low, the appliance will start to preserve free RAM by swapping out the contents of the memory to the hard disk (swap space). The performance will be sub-optimal if swap space is being used due to time and resources spent writing and reading to the hard-disk.
[Expert@Zulu]# free –k -t
total used free shared buffers
Mem: 2055120 1897424 157696 0 98732
-/+ buffers/cache: 1101004 954116
Swap: 4192912 735980 3456932
Total: 6248032 2633404 3614628 [Expert@Zulu]#
Swap space usage may indicate not enough memory is installed in the appliance. The kernel is
32 bit and can use up to 4GB. It is recommended to upgrade the memory if less than 4GB of RAM
For further information about the amount of RAM that is supported by SecurePlatform refer to:
sk22343: What is the maximum memory supported by SecurePlatform?
The firewall‟s memory usage can be examined by using the command:
The output of this command is vast and can be difficult to understand as not all the output is intuitive. The statistics that need to be checked to ensure memory is healthy are:
· hash kernel memory „hmem‟
· system kernel memory „smem‟
· kernel memory „kmem‟.
[Expert@Zulu]# fw ctl pstat | more
Machine Capacity Summary:
Memory used: 7% (128MB out of 1638MB) - below low watermark
Concurrent Connections: 21% (43253 out of 199900) - below low watermark
Aggressive Aging is not active
Hash kernel memory (hmem) statistics:
Total memory allocated: 142606336 bytes in 34782 4KB blocks using 34 pools
Initial memory allocated: 20971520 bytes (Hash memory extended by
Memory allocation limit: 335544320 bytes using 512 pools
Total memory bytes used: 39254196 unused: 103352140 (72.47%) peak:
Total memory blocks used: 10335 unused: 24447 (70%) peak:
Allocations: 3375437074 alloc, 0 failed alloc, 3375001310 free
System kernel memory (smem) statistics:
Total memory bytes used: 188577580 peak: 227270504
Blocking memory bytes used: 1958392 peak: 2205256
Non-Blocking memory bytes used: 186619188 peak: 225065248
Allocations: 979925174 alloc, 0 failed alloc, 979924513 free, 0 failed
Kernel memory (kmem) statistics:
Total memory bytes used: 84876956 peak: 177110948
Allocations: 3375820431 alloc, 0 failed alloc, 3375384380 free, 0 failed
External Allocations: 0 for packets, 31589936 for SXL
In the above example there are no hmem, smem, kmem failed allocations.
Presence of „hmem‟ failed allocations indicates that the hash kernel memory was full. This is not a serious memory problem but indicates there is a configuration problem. The value assigned to the hash memory pool, (either manually or automatically by changing the number concurrent
connections in the capacity optimization section of a firewall) determines the size of the hash kernel memory. If a low hmem limit was configured it leads to improper usage of the OS memory. See
„Capacity Optimization‟ in the „Firewall Health Checks‟ section for further information.
Presence of „smem‟ failed allocations indicates that the OS memory was exhausted or there are large non-sleep allocations. This is symptomatic of a memory shortage. If there are failed smem allocations and the memory is less than 2 GB, upgrading to 2GB may fix the problem. Decreasing
the TCP end timeout and decreasing the number of concurrent connections can also help reduce memory consumption.
Presence of „kmem‟ failed allocations means that some applications did not get memory. This is usually an indication of a memory problem; most commonly a memory shortage. The natural limit is
Memory shortage sometimes indicates a memory leak. In order to troubleshoot memory shortage, stop the load you need to stop the load and let connections close. If the memory consumption returns back to normal, you are not dealing with a memory leak. Such shortage might happen when traffic volumes are too high for the device capacity. If the memory shortage happens after a change in the system or the environment, undo the change, and check whether kmem memory consumption goes down.