= How to reboot a physical server and guests = On occasion we need to reboot a physical server and all of it's guests (often due to a kernel upgrade). This is an intensive process and can take a long time as many servers need to run fsck on reboot which demands intensive disk activity. This page documents the currently recommended process for such reboots. == Make sure all guests on a host are updated == * run package updates {{{ apt-get update apt-get -s dist-upgrade }}} * if the server needs upgrades {{{ apt-get dist-upgrade }}} == Check available disk space == * Make sure there is available space on the logical volumes, and take appropriate steps if not, see [[extend-disk-on-kvm-guest]] * if you added disk space from the host, reboot the guest with {{{ shutdown -h now }}} == Determine if the guest will fsck on reboot == * On kvm guests or vserver hosts check when the next fsck is scheduled for all logical volumes with: {{{ for i in $(ls /dev/mapper/vg_* | grep -v swap); do tune2fs -l $i | grep Next; done }}} * '''e.g.''' {{{ 0 malcolm:~# for i in $(ls /dev/mapper/vg_* | grep -v swap); do tune2fs -l $i | grep Next; done Next check after: Fri Oct 11 12:12:47 2013 Next check after: Fri Oct 11 12:12:28 2013 Next check after: Thu Aug 29 23:16:36 2013 Next check after: Fri Oct 11 13:07:33 2013 Next check after: Fri Oct 11 13:08:17 2013 Next check after: Fri Oct 11 13:08:40 2013 0 malcolm:~# }}} * If a guest will fsck on reboot (i.e. the date from the above is earlier than the current date). Reboot a kvm guest from root@GUEST with. You can watch reboot progress with `ssh -t guest@host screen -x` {{{ shutdown -r now }}} '''Do this for all guests on the host.''' == Take down the host's guests == '''FIXME: Add better information for vservers, this is currently just about kvm''' * From `root@host` check running services: {{{ cd /etc/service for x in *; do sv status $x; done }}} * Take down each guest's service: {{{ sv down GUESTNAME }}} * Make sure the guest has gone down, this may take a few seconds. * If the guest has not gone down in a short time, you may need to manually restart from `root@guest` with: {{{ shutdown -h now }}} * Check to make sure all guests are down, repeat the status command above. You should see a line that starts with `down: GUESTNAME` for all guests. == Reboot the host == * Assuming all the guests are down, you should be able to restart the server. * Get access to the serial console * Telehouse use [[telehouse_serial_access]] * XO use [[xo_serial_access]] * Shut down the system from `root@host` with {{{ shutdown -r now }}} * Watch the reboot process from the serial console and enter the encrypted password when requested (accessed via keyringer)