I have a server (virtual) running Linux (Ubuntu 16.04 amd64). It has 8gb memory allocated, and it's all being used, but i don't know by what.

root@server:~# free -k
              total        used        free      shared  buff/cache   available
Mem:        8176980     7892288      121580       22000      163112       94516
Swap:       1572860      206800     1366060

root@server:~# grep VmHWM /proc/*/status | awk 'BEGIN {tot=0} {tot+=$2} END {print tot}'

Why doesn't the sum of VmHWM sum up to something closer to 8GB? And how can i find out what is eating up memory (and causing the server to swap)? And is there some good site that explains Linux memory/resource usage in a detailed but clear way? :)

Some more info:

root@server:~# uname -a
Linux server 3.13.0-67-generic #110-Ubuntu SMP Fri Oct 23 13:24:41 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

root@server:~# cat /proc/meminfo 
MemTotal:        8176980 kB
MemFree:          151200 kB
Buffers:           10420 kB
Cached:            77100 kB
SwapCached:        27780 kB
Active:          2870576 kB
Inactive:         837248 kB
Active(anon):    2834228 kB
Inactive(anon):   808112 kB
Active(file):      36348 kB
Inactive(file):    29136 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:       1572860 kB
SwapFree:        1359252 kB
Dirty:               176 kB
Writeback:             0 kB
AnonPages:       3594152 kB
Mapped:            41096 kB
Shmem:             22036 kB
Slab:              65724 kB
SReclaimable:      39444 kB
SUnreclaim:        26280 kB
KernelStack:        5240 kB
PageTables:        37636 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:     5661348 kB
Committed_AS:    4266360 kB
VmallocTotal:   34359738367 kB
VmallocUsed:      289196 kB
VmallocChunk:   34359442456 kB
HardwareCorrupted:     0 kB
AnonHugePages:   2009088 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:       65472 kB
DirectMap2M:     8323072 kB

Try comparing it at any time with result of vmrss see if it match.

Also try disabling transparent hugepages.And check with virtualization admin and see if the whole 8 gb are reserved or not.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.