Disclaimer: This article is a blogger original article, shall not be reproduced without the bloggers allowed. https://blog.csdn.net/qiuchangyong/article/details/89974022
To add a swap partition, FreeBSD and other linux server command a little different, try to go through the following steps pro-test available on FreeBSD11.1.
1. Create the swap file, /usr/swap0:
# dd if=/dev/zero of=/usr/swap0 bs=1024k count=512
2. Set the proper permissions on /usr/swap0:
# chmod 0600 /usr/swap0
3. Enable the swap file in /etc/rc.conf:
# swapfile="/usr/swap0" # Set to name of swap file
4. Swap space will be added on system startup. To enable the swap file immediately, specify a free memory device.
# mdconfig -a -t vnode -f /usr/swap0 -u 0 && swapon /dev/md0