Cum sa maresti o partitie SWAP pe LVM

Servere cu prea putin SWAP sau chiar deloc, care necesita SWAP. Atunci apare aceasta problema de a face increase la SWAP (fara a da reboot la server).

In acest exemplu eu am 512MB SWAP pe un server cu 16GB RAM.
Deoarece am ceva containere java care ruleaza pe server, si au nevoie de ram+swap, e nevoie de 8GB SWAP:

root@localhost:/root # free -m
total used free shared buffers cached
Mem: 16050 9484 6566 0 13 46
-/+ buffers/cache: 9424 6626
Swap: 511 0 511

echo 3 > /proc/sys/vm/drop_caches

root@localhost:/root # cat /proc/swaps
Filename Type Size Used Priority
/dev/mapper/rootvg-swap partition 511 0 -33

swapoff /dev/mapper/rootvg-swap

lvextend -L 8G /dev/mapper/rootvg-swap

mkswap /dev/mapper/rootvg-swap

swapon /dev/mapper/rootvg-swap

(sau swapon -a)

Elibereaza SWAP; mareste partitia; markeaza noua partitia ca SWAP; activam noua partite SWAP ca fiind activa.

root@localhost:/root # free -m
total used free shared buffers cached
Mem: 16050 9484 6566 0 13 46
-/+ buffers/cache: 9424 6626
Swap: 8191 0 8191