You'd probably want to do the filesystem unmount dance first: echo 1 > /proc/sys/kernel/sysrq echo u > /proc/sysrq-trigger dmesg --follow \ | grep -qm1

You'd probably want to do the filesystem unmount dance first: echo 1 > /proc/sys/kernel/sysrq echo u > /proc/sysrq-trigger dmesg --follow \ | grep -qm1 'Emergency Remount complete' echo o > /proc/sysrq-trigger ...least putting a bit too much trust in ext4/btrfs/zfs journalling.