what are these commands used for? FORTIGATE

Diag hardware deviceinfo disk----command will be able to see number of available disk, number of partitions, information about virtual disk.
photon-kvm44 # diag hardware deviceinfo disk

Disk SYSTEM(boot) 2.0GiB type: IDE [Virtio Disk] dev: /dev/vda
partition 123.0MiB, 18.0MiB free mounted: Y label: dev: /dev/vda1(boot) start: 2048
partition 1.7GiB, 1.5GiB free mounted: Y label: dev: /dev/vda2(boot) start: 526336

Disk Virtual-Disk ref: 16 16.0GiB type: IDE [Virtio Disk] dev: /dev/vdb
partition ref: 17 15.7GiB, 15.6GiB free mounted: Y label: LOGUSEDX89B116C4 dev: /dev/vdb1 start: 2048

Total available disks: 2
Max SSD disks: 8 Available storage disks: 1

get hardware cpu: It will give complete information about CPU
photon-kvm44 # get hardware cpu
processor : 0
vendor_id : AuthenticAMD
cpu family : 23
model : 49
model name : AMD EPYC 7452 32-Core Processor
stepping : 0
microcode : 0x1000065
cpu MHz : 2345.444
cache size : 512 KB
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm up rep_good nopl extd_apicid pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm cmp_legacy svm cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw perfctr_core arat xsaveopt npt nrip_save fsgsbase tsc_adjust avx2 smep bmi2 rdseed
bogomips : 4690.88
TLB size : 1024 4K pages
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management:

get sys status: You will be able to see information about fortigate firewall, last reboot reason, log disk available or not, serial number, database definition version etc