Differences

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--- tutorial:adm:server_os_updates [2019/12/16 15:17]
fiserp [Performing the OS update]
+++ tutorial:adm:server_os_updates [2019/12/16 15:28]
fiserp [Solving issues]
@@ Line 73: / Line 73: @@
 ==== Solving issues ====
-During maintenance actions, it is necessary to know:
+For maintenance actions, it is necessary to:
-  * How long each task will take **TT**.
+  * Know how long each task will take and to measure the task duration when actually performing them.
-  * How long the whole maintenance will take **MT**.
+    * If tasks take longer than expected, you know if you can match the maintenance window or not.
-    * This is not simply a sum od **TT**s, you should add some extra time **ET** to have a proper cushion.
+  * Know how long the whole maintenance will take (maintenance time **MT**).
-  * How long (at worst) the whole rollback will take **RT**.
+    * This is not simply a sum of task times, you should add some extra time (**ET**) to have a proper cushion.
-  * To have a maintenance window that spans at least **MT**+**RT** with some extra time **ET**.
+  * Know how long (at worst) the whole rollback will take (rollback time **RT**).
-    * You are not able to safely perform the maintenance in shorter window - if something goes wrong, you need at most **RT** time to perform the rollback!
+  * Have a maintenance window that spans at least **MT**+**RT** with some extra time **ET**.
-    * If you do not have any **ET**, if anything goes wrong you have to perform rollback procedure. Therefore, **ET** gives you some time you can spend on solving the issue so you can continue with updates.
+    * You are not able to safely perform the maintenance in shorter window, there is simply not enough time. If something goes wrong, you need at most **RT** time to perform the rollback!
+    * If you do not have any **ET**, if anything goes wrong you have to perform rollback procedure. Therefore, **ET** gives you some time you can spend on solving the issue so you can carry on with updates.
+You should have a rollback procedure that can safely restore the deployment. This depends on your environment.
+Fortunately, in most cases it simply means restoring the snapshot of the virtual machine. After restoring the snapshot, you have to perform tests (with test use-cases) to confirm the rollback was performed correctly.
+In more complicated cases, restoring the IdM database or application WAR may be the way.