How much RAM do I have free?

Question

linux

Debian 9.
Installed nginx mysql-server php-fpm php-mysql php7.0-curl php7.0-mcrypt php7.0-mbstring vsftpd And that's it.
The project is simple. Requests are relatively primitive.
Once every 10 minutes, a relatively high-load query occurs (fetching 200,000 values).
Those. system operation by type no request, light request, no request ... high-loaded request and then 10 minutes again quiet
and smooth.
Previously, the project worked on the minimum VPS tariff (ovz) with 512MB of RAM.

Now it works on the "initial-middle" tariff (KVM) with 2 GB of memory.

And, judging by the schedule, is almost all the memory occupied there?
From the terminal

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Tue Sep 25 09:33:26 2018 from 5.172.4.132
[email protected]:~# free -m
              total        used        free      shared  buff/cache   available
Mem:           2004         138          97          18        1768        1686
Swap:          2047           0        2047
[email protected]:~# vmstat -s
      2052476 K total memory
       141828 K used memory
       506592 K active memory
      1347300 K inactive memory
       100044 K free memory
        76812 K buffer memory
      1733792 K swap cache
      2097148 K total swap
           20 K used swap
      2097128 K free swap
        37846 non-nice user cpu ticks
            0 nice user cpu ticks
        23719 system cpu ticks
      3411706 idle cpu ticks
         2241 IO-wait cpu ticks
            0 IRQ cpu ticks
        17014 softirq cpu ticks
        60918 stolen cpu ticks
       374367 pages paged in
      4684636 pages paged out
            0 pages swapped in
            7 pages swapped out
      5267247 interrupts
      8565319 CPU context switches
   1537848357 boot time
        27178 forks
[email protected]:~#

How much RAM do I have free?

Answer 1

I’ll analyze the output of free -m
, you have free 97 megabytes
used for buffers and file system caches 1768 megabytes (of which 1589 megabytes can be allocated to new or current processes if they request memory from the OS)
Total available for use 1686 megabytes

Answer 2

linux ate my ram!/
1686mb available. See available in the free output.
And it is impossible to monitor the kvm memory of the virtual machine from the host. The host, as expected, sees that the guest is using all the memory.

Answer 3

On the chart with the cache is indicated. actually consumed used 138