When running on the server to free -hcheck the memory usage today, I accidentally found such a line -/+ buffers/cache, and I don’t know what it means for a while.
Later, after searching for information, I learned that:
-/+ buffers/cache indicates the memory space that the operating system can actually use now, which is equivalent to the first line Mem( used - buffers - cachedie 852M - 25M - 300M = 526M), which means Memthat it is not actual Use the space, -/+ buffers/cacheyes. So why is this the case?
Because Memthe bufferssum in the middle is cachedactually the system cache, which is the data imported by the system to enhance the performance of the computer, which can be released at any time, and the -/+ buffers/cachestatistics are the remaining memory space after these caches are released, so it -/+ buffers/cacheis the real Free memory space.
Refer to the appendix
[root@C20220819227253 ~]# free -h
total used free shared buffers cached
Mem: 990M 859M 131M 38M 28M 303M
-/+ buffers/cache: 527M 463M
Swap: 0B 0B 0B