Question
What would be the recommended backup procedures to ensure recovery from a data loss. ie. host crashes or someone deletes a large number of tasks/sessions/ etc..
Is a database hot backup a good practice?
Answer
If you are doing a hot
backup there is a little risk that some
of the more dynamic files are corrupted since the backup would copy them at uncontrolled times (during a write for example?).
Still, it’s better than nothing, and the risk is low, if you backup at a time
of lower activity (which we strongly recommend).
We would recommend to
consider the procedures described below as best practices:
1) The cold backup at the system level is great for the structure of the
file system, permissions, configuration files, logs etc…
It captures everything. It should be a backup with
$U stopped to make sure the backup is
consistent.
2) Uxbck uni: It backs up only data
and indexes files – which is confirmed in the Administration Guide:
The online backup includes only database files
(.dta and .idx extensions) and can be done for each Area
It means you are missing a number of things, like
internal uproc scripts, and configuration files – and job logs
Still, it is not to be ignored, because it can be
run while $U is ON, and get these important data files safely, which our above method in (1) does not.
3) You can export the objects
themselves. It is therefore very granular. It is very easy to recover 1
individual object that someone deleted by mistake for example. You don’t want to
go back to a full backup just for that! Here, you could re-import a single uproc with minimal headache by using this method.
You can find the syntax for the extractionuxext and insertion commanduxins in the Commands Guide for Dollar Universe.