Below are the list of commands where you can use to check and obtain memory information in the Unix or Linux operating system.
vmstat Command
### COMMAND ###
vmstat
### OUTPUT ###
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
r b swpd free buff cache si so bi bo in cs us sy id wa st
0 0 0 656351788 47736 12075728 0 0 119 126 0 0 3 0 97 0 0
top Command
### COMMAND ###
top
### OUTPUT ###
top - 16:53:46 up 113 days, 15:53, 1 user, load average: 1.09, 0.57, 0.39
Tasks: 345 total, 1 running, 344 sleeping, 0 stopped, 0 zombie
%Cpu(s): 1.3 us, 0.4 sy, 0.0 ni, 98.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
MiB Mem : 881880.5+total, 640969.3+free, 229071.9+used, 11839.31+buff/cache
MiB Swap: 0.000 total, 0.000 free, 0.000 used. 643806.2+avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
66462 sidadm 20 0 0.215t 0.211t 4.151g S 12.62 25.09 2040:24 hdbindexserver
66013 sidadm 20 0 9873708 5.221g 624796 S 5.648 0.606 75:09.33 hdbnameserver
3229 root 20 0 4980484 368512 25132 S 1.993 0.041 2035:21 wdavdaemon
3974 root 20 0 29756 10168 5244 S 1.329 0.001 120:02.57 saposcol
5493 root 20 0 274940 32232 9880 S 1.329 0.004 2046:28 python3
meminfo Command
### COMMAND ###
cat /proc/meminfo | more
### OUTPUT ###
MemTotal: 903045716 kB
MemFree: 656352056 kB
MemAvailable: 659257124 kB
Buffers: 47736 kB
Cached: 11691768 kB
SwapCached: 0 kB
Active: 240391812 kB
Inactive: 4034268 kB
Active(anon): 237096200 kB
Inactive(anon): 792116 kB
Active(file): 3295612 kB
Inactive(file): 3242152 kB
Unevictable: 10768 kB
Mlocked: 10768 kB
SwapTotal: 0 kB
SwapFree: 0 kB
Dirty: 76 kB
Writeback: 0 kB
AnonPages: 232695292 kB
Mapped: 5487544 kB
Shmem: 5192884 kB
Slab: 528568 kB
SReclaimable: 383984 kB
SUnreclaim: 144584 kB
KernelStack: 30240 kB
PageTables: 505896 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 451522856 kB
Committed_AS: 270682756 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 0 kB
VmallocChunk: 0 kB
HardwareCorrupted: 0 kB
AnonHugePages: 36864 kB
ShmemHugePages: 0 kB
ShmemPmdMapped: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 1413056 kB
DirectMap2M: 238710784 kB
DirectMap1G: 677380096 kB
free -g/-m Command
### COMMAND ###
free -g
### OUTPUT ###
total used free shared buff/cache available
Mem: 861 223 625 4 11 628
Swap: 0 0 0
