Memory used is high, but user data in RAM is low, and disk usage is low also.What's the reason?

hello, all.
os version: CentOS Linux release 7.3.1611
Couchbase version: 4.5.1-2844 Community Edition (build-2844)
server total memory: 16G
user data in ram: 1.94G
disk usage: 1.13G
bucket’s number: 56
index’s number: 9
view’s number: 52

i use linux command ‘top’, find that memory used (about 11G) is much higher than user data in RAM and disk usage as above shown.
i can’t find the reason why memory used is so much.
is the number of bucket too many? or is there any wrong setting i made? or any operation i did cause this problem like as creating indexs, views ?……
anyone can help me and tell me why?

figure as blow:

What figure are you looking at in top ?

Note if you’re looking at the total used, the remainder is likely just general OS caching - see :slight_smile:

Thanks, drigby. This is the figure. And i also use ‘free -m’ to check, the result was similar to ‘top’

Today, i got a new problem. at the condition above of my server, i created some new buckets, and then i wanted to create views and indexes on these new buckets.but after views created(actually some got failure, timeout), the memory used kept more higher and has never been lowered. it cost almost all memory and swap area, the process’s VIRT was 30g+.I felt the machine will crash at any moment. Any idea about this? I doubt i’m a trouble maker…crying…