PA-7080 firewall shows high utilization (even 100%) of the management plane swap space

For the example chosen below, the show system resources follow output shows 15572256 avail Mem (approximately 15.5 GB). This indicates that there is a substantial amount of physical memory available for processes, despite the swap being fully utilized. As long as the avail Mem value is healthy and not decreasing rapidly, the high swap utilization can generally be ignored.

FW(passive)> show system resources follow
top - 09:35:08 up 421 days, 13:07, 1 user, load average: 1.14, 0.92, 0.88
Tasks: 372 total, 2 running, 228 sleeping, 0 stopped, 1 zombie
%Cpu(s): 3.7 us, 0.2 sy, 0.0 ni, 95.9 id, 0.0 wa, 0.1 hi, 0.1 si, 0.0 st
KiB Mem : 32601840 total, 4439556 free, 16405000 used, 11757284 buff/cache
KiB Swap: 956 total, 0 free, 956 used. 15572256 avail Mem
=========================
Additionally, the disk space is seen in a healthy state
> show system disk-space
Filesystem Size Used Avail Use% Mounted on
/dev/md2 30G 13G 17G 44% / 

none 16G 136K 16G 1%

/dev /dev/md5 48G 8.0G 38G 18% /opt/pancfg

/dev/md6 24G 12G 12G 51% /opt/panrepo

tmpfs 16G 302M 16G 2% /dev/shm

cgroup_root 16G 0 16G 0% /cgroup

/dev/md8 32G 18G 13G 60% /opt/panlogs

tmpfs 12M 44K 12M 1% /opt/pancfg/mgmt/ssl/private

PA-7080, PA-3200, PA-400, and PA-5450
Any PAN OS

Customer might receive an alert for 90% Disk Space Used:
 

Palo Alto Networks firewalls, including the PA-7080 and other series like PA-3200, PA-400, and PA-5450, are designed with a relatively small swap memory area (often around 1MB, 8MB, or 1GB) on the management plane. Your show system resources follow output confirms this with KiB Swap: 956 total, which is approximately 0.9MB

The Linux kernel, which the firewall's management plane runs on, manages memory by moving inactive process memory to swap space, even if ample physical RAM is available. Because the total swap space is small, it can quickly become fully utilized, leading to 100% reported usage. This is considered a normal operational characteristic and is by design.

Focus on Available Memory (avail Mem) >> For PAN-OS versions 9.0 and later, the most accurate metric for understanding the system's memory health is avail Mem (Available Memory), not the free memory or swap usage.

Free Memory is memory completely unused.

Available Memory includes free memory plus memory currently used by the operating system for caching and buffering. This cached memory can be quickly reclaimed by applications if needed, making it "available" even if it's currently in use. 

Check How To Troubleshoot High Management Plane CPU Usage for more information on how to reduce the load on Management Plane.
If your device is a Panorama VM then check how to Increase CPUs and Memory on the Panorama Virtual Appliance.
If your device is a PA-VM then make sure that you have allocated the necessary resources to it, refer to VM-Series System Requirements and the option to increase the memory (RAM) of your FW.
For VM-Flex post 10.2 refer to Maximum Limits Based on Tier and Memory
For VM-Flex pre 10.2 refer to Maximum Limits Based on Tier and Memory.