From a9023144352f503c96bf6cfabbb25e86ce398f91 Mon Sep 17 00:00:00 2001 From: Dietmar Maurer Date: Tue, 22 Nov 2016 07:40:01 +0100 Subject: [PATCH] ha-manager.adoc: add new section Node Maintenance --- ha-manager.adoc | 51 +++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 45 insertions(+), 6 deletions(-) diff --git a/ha-manager.adoc b/ha-manager.adoc index 944ad48..e1b0df8 100644 --- a/ha-manager.adoc +++ b/ha-manager.adoc @@ -624,13 +624,52 @@ killing its process) * *after* you fixed all errors you may enable the service again -Node Power Status ------------------ +Node Maintenance +---------------- -If a node needs maintenance you should migrate and or relocate all -services which are required to run always on another node first. -After that you can stop the LRM and CRM services. But note that the -watchdog triggers if you stop it with active services. +It is sometimes possible to shutdown or reboot a node to do +maintenance tasks. Either to replace hardware, or simply to install a +new kernel image. + + +Shutdown +~~~~~~~~ + +A shutdown ('poweroff') is usually done if the node is planned to stay +down for some time. The LRM stops all managed services in that +case. This means that other nodes will take over those service +afterwards. + +NOTE: Recent hardware has large amounts of RAM. So we stop all +resources, then restart them to avoid online migration of all that +RAM. If you want to use online migration, you need to invoke that +manually before you shutdown the node. + + +Reboot +~~~~~~ + +Node reboots are initiated with the 'reboot' command. This is usually +done after installing a new kernel. Please note that this is different +from ``shutdown'', because the node immediately starts again. + +The LRM tells the CRM that it wants to restart, and waits until the +CRM puts all resources into the `freeze` state. This prevents that +those resources are moved to other nodes. Instead, the CRM start the +resources after the reboot on the same node. + + +Manual Resource Movement +~~~~~~~~~~~~~~~~~~~~~~~~ + +Last but not least, you can also move resources manually to other +nodes before you shutdown or restart a node. The advantage is that you +have full control, and you can decide if you want to use online +migration or not. + +NOTE: Please do not 'kill' services like `pve-ha-crm`, `pve-ha-lrm` or +`watchdog-mux`. They manage and use the watchdog, so this can result +in a node reboot. [[ha_manager_package_updates]] -- 2.39.2