I have a Redhat system which has a total of 64GB RAM. As per free output it is utilizing 47GB of RAM.
free -g
total used free shared buffers cached
Mem: 62 59 2 0 3 8
-/+ buffers/cache: 47 15
Swap: 7 0 7
But when I added the individual memory usage of the processes, total memory usage value appears to be around 37GB much less than 47GB. Can someone please explain why there is a difference of 10GB in these two.
I tried reading many man pages and articles. But none of them were helpful for a mere mortal like me.
Is there a way to visualize every bit (pun intended) of the used memory of free output (in my case 47GB)?
ps -eo size | awk '{mem += $1} END {print mem/1024/1024}'
37.2644
ps aux |awk '{rsstotal += $6} END {print rsstotal/1024/1024}'
17.9053
This is what /proc/meminfo shows:
cat /proc/meminfo
MemTotal: 65963224 kB
MemFree: 2923708 kB
Buffers: 3716988 kB
Cached: 9134512 kB
SwapCached: 36260 kB
Active: 21634524 kB
Inactive: 9797536 kB
Active(anon): 16855836 kB
Inactive(anon): 1725656 kB
Active(file): 4778688 kB
Inactive(file): 8071880 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 8241144 kB
SwapFree: 8066288 kB
Dirty: 3720 kB
Writeback: 0 kB
AnonPages: 18561916 kB
Mapped: 31756 kB
Shmem: 732 kB
Slab: 14282976 kB
SReclaimable: 13920332 kB
SUnreclaim: 362644 kB
KernelStack: 33944 kB
PageTables: 71732 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 32834148 kB
Committed_AS: 21413336 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 262076 kB
VmallocChunk: 34359450304 kB
HardwareCorrupted: 0 kB
AnonHugePages: 0 kB
HugePages_Total: 8192
HugePages_Free: 7840
HugePages_Rsvd: 55
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 8192 kB
DirectMap2M: 2088960 kB
DirectMap1G: 65011712 kB
Can someone please help.
