Safely increase Swap memory on Node with Vm/CT on It.

[Bidi]

Hello guys,

I got 4 servers on the same cluster on all of them there ar CT's and VM's.
Every node it has Minimum 64 GB Ram and maximum 256 GB Ram.

The Ram usage / node (server) is around 20%-30% of the total memory ram, i just noticed now on all the servers the swap is 8GB Only :| and on 2 nodes is full so is not ok at all.

I do have to increase the Swap but i dont whant to reinstall the node and i have to do it safetly because of the CT/VM's on the node.

Dose anyone know hot to do this in safe way and not losing any data ?

All the nodes use proxmox 5.4-13

I just dont understand why dose it make the same amount of ram, like i got 4 servers with proxmox 3.4 i just installed doing nothink alse and if the server has 64Gb Ram he made the Swap 64Gb Two so i was thinking is the same for proxmox 5.4, i didnt even realize is not making it, i migrate the entire servers all ok and i spoted now :|

Thank you

root@d4:~# df -h
Filesystem            Size  Used Avail Use% Mounted on
udev                   32G     0   32G   0% /dev
tmpfs                 6.3G  555M  5.8G   9% /run
/dev/mapper/pve-root   94G   44G   46G  50% /
tmpfs                  32G   66M   32G   1% /dev/shm
tmpfs                 5.0M     0  5.0M   0% /run/lock
tmpfs                  32G     0   32G   0% /sys/fs/cgroup
/dev/mapper/pve-data  1.7T  959G  682G  59% /var/lib/vz
/dev/fuse              30M   80K   30M   1% /etc/pve
root@d4:~#

 

[t.lamprecht]

HI,

df is for filesystem disk usage, not memory/swap, use: free -h

You could first check what got swapped out, for example the following one liner shows you the top 10 processes with swap:
for file in $(find /proc/*/status -exec grep -q 'VmSwap' {} \; -print); do awk '/^(VmSwap|Pid|Name)/{printf $2 " " $3 }END{ print ""}' $file; done | sort -k 3 -n -r | head

Note, those processes are not the cause of the "swapping out", they, or parts of their memory usage, just seemed to be not used so that swapping them out won't impact the system much.

What's your swappiness: sysctl vm.swappiness

What's your memory use:
top -b -E m -o +%MEM | head -15