Tech How much RAM my server is actually using ?

[freecartoonporn]

my server shows

free -h
              total        used        free      shared  buff/cache   available
Mem:           125G         43G         16G        1.2G         65G         79G
Swap:          4.0G        2.3G        1.7G

this box has 128 gigs of ram.

am i really using all of it ? or i can move to 64 gigs ram server ?

server is using
mysql innodb_buffer_pool_size = 70G (actually database size is only 20 GB )
elastic 15 gb

thanks for your time.

[shake]

I would install htop, it has a more useful output.

[freecartoonporn]

I would install htop, it has a more useful output.

i have htop installed and it shows.

[ghjghj]

free -h
available
79G

[NatalieMojoHost]

The deal with Linux is: it will try to use all of the RAM in the system for speeding up the filesystem and other things. That's what the buf/cache is.

The shortest answer is - you have 79GB available and 43GB hard in-use, but Linux is taking another 65GB and using it to slightly speed up your system in other ways.

If another process needs that memory, say MySQL or Elasticsearch, it's able to pull it out of that buffer/cache pool and away from the filesystem. But it will pull it from the 16GB free first.

Hope this helps clear things up for you.

[kjs]

If you really want to understand whats happening on the server install netdata.

https://github.com/netdata/netdata

You will have to enable the hooks for whatever your architecture is e.g. nginx/apache php etc.

VPS is even more misleading when it comes to the standard tools because they usually don't include wait times, swaps, connection pools running out, etc.

[wankawonk]

The deal with Linux is: it will try to use all of the RAM in the system for speeding up the filesystem and other things. That's what the buf/cache is.

The shortest answer is - you have 79GB available and 43GB hard in-use, but Linux is taking another 65GB and using it to slightly speed up your system in other ways.

If another process needs that memory, say MySQL or Elasticsearch, it's able to pull it out of that buffer/cache pool and away from the filesystem. But it will pull it from the 16GB free first.

Hope this helps clear things up for you.

solid answer

I would recommend just using top, add up the "free" and "buf/cache" columns and that's how much you have "free". though you should always leave some buf/cache to speed up any potential swapping.

Important elasticsearch detail: If your elasticsearch shard size exceeds the amount of heap space you allocate to it, elasticsearch will get a big speed boost from having memory available for buf/cache. So be careful to monitor that. don't just assign all your buf/cache to (for example) redis because it might severely impact your elasticsearch performance.

[freecartoonporn]

The deal with Linux is: it will try to use all of the RAM in the system for speeding up the filesystem and other things. That's what the buf/cache is.

The shortest answer is - you have 79GB available and 43GB hard in-use, but Linux is taking another 65GB and using it to slightly speed up your system in other ways.

If another process needs that memory, say MySQL or Elasticsearch, it's able to pull it out of that buffer/cache pool and away from the filesystem. But it will pull it from the 16GB free first.

Hope this helps clear things up for you.

solid answer

I would recommend just using top, add up the "free" and "buf/cache" columns and that's how much you have "free". though you should always leave some buf/cache to speed up any potential swapping.

Important elasticsearch detail: If your elasticsearch shard size exceeds the amount of heap space you allocate to it, elasticsearch will get a big speed boost from having memory available for buf/cache. So be careful to monitor that. don't just assign all your buf/cache to (for example) redis because it might severely impact your elasticsearch performance.

thank you, i wan planning to move my server to 64 gigs ram server, i guess more ram is always better.

[rowan]

my server shows

free -h
              total        used        free      shared  buff/cache   available
Mem:           125G         43G         16G        1.2G         65G         79G
Swap:          4.0G        2.3G        1.7G

I'm not so familiar with Linux, but the fact that you have some swap used, especially a couple of gigs, may suggest that at some point the RAM usage was a lot higher, and the system had to swap out an idle task.

[freecartoonporn]

I'm not so familiar with Linux, but the fact that you have some swap used, especially a couple of gigs, may suggest that at some point the RAM usage was a lot higher, and the system had to swap out an idle task.

maybe because of swappiness set to 60, so it tends to swap more often.