Sometimes your swap is not large enough

[root@server ~]# free -g
total used free shared buff/cache available
Mem: 23 3 13 0 7 19
Swap: 1 0 1
[root@server ~]# grep swap /etc/fstab
/dev/mapper/vg00-swapvol swap swap defaults 0 0
[root@server ~]# swapoff /dev/mapper/vg00-swapvol
[root@server ~]# lvextend -L10g $_
Size of logical volume vg00/swapvol changed from 2.00 GiB (16 extents) to 10.00 GiB (80 extents).
Logical volume vg00/swapvol successfully resized.
[root@server ~]# mkswap $_
mkswap: /dev/mapper/vg00-swapvol: warning: wiping old swap signature.
Setting up swapspace version 1, size = 10485756 KiB
no label, UUID=xxx
[root@server ~]# swapon $_
[root@server ~]# free -g
total used free shared buff/cache available
Mem: 23 3 13 0 7 19
Swap: 9 0 9

By karlo