|Titel||Fix possible accidental removal of all new style RRDs (var/check_mk/rrd) when downgrading from 1.4 or newer|
|Check_MK Edition||Check_MK Raw Edition (CRE)|
|Level||2 - Wichtige Änderung|
|Kompatibilität||Compatible - no manual interaction needed|
When downgrading a site from 1.4 or newer to a 1.2.8 version it could happen that all metrics (new style RRD files in var/check_mk/rrd) were deleted by "omd update".
This could only happen when "omd update" command is executed with the option "--conflict=install" which is normally only used for scripting the update procedure. You need to know that this is used when performing site updates/downgrades with the Check_MK Appliance.
Manual invocations of "omd update" are not directly affected. When executing this manually, OMD asks for confirmation to delete the directory. The user can always choose "keep" to prevent the deletion of this directory.
In case you need to perform a downgrade from 1.4 or newer, you should only downgrade to a 1.2.8 release 1.2.8p27 or newer. After this downgrade, you could continue downgrading to older 1.2.8 releases, if you like.