Linux

Check current swappiness cat /proc/sys/vm/swappiness Change swappiness sudo vim /etc/sysctl.conf set vm.swappiness = 10 apply setting: sudo sysctl -p

1. Create SWAP file1. Create SWAP file dd if=/dev/zero of=/opt/.swap bs=1024k count=20 （count is what SWAP size you need, MB） mkswap /opt/.swap 2. Active SWAP swapon /opt/.swap 3. Check free 4. Disable SWAP, wipe SWAP file. if you just swapoff SWAP not delete SWAP file, SWAP will reactive when next restart. swapoff /opt/.swap` `rm /opt/.swap

The nohup command only writes to nohup.out if the output is otherwise to the terminal. If you redirect the output of the command somewhere else – including /dev/null – that’s where it goes instead. nohup command >/dev/null 2>&1 # doesn't create nohup.out If you’re using nohup, that probably means you want to run the command in the background by putting another & on the end of the whole thing: nohup command >/dev/null 2>&1 & # runs in background, still doesn't create nohup.out, no error file create

1582年2月，罗马教廷要求从1582 年10月中减去10天