v.: 2020-09-04
Copyright of the European Union is effective (Copyright EU) (c) 2019 GENEREX Systems GmbH, Hamburg, Germany, All rights reserved
TEL +49(40)22692910 - EMAIL generex@generex.de - WEB www.generex.de (This and all other product datasheets are available for download.)
25
Preparing RCCMD for the vSAN
At vmware settings, enable “Hosts are also vSAN nodes”
To manage the shutdown routine, ensure that the RCCMD appliance must be located outside the VSAN cluster.
Once you have activated the vSAN mode, you will get additional menus:
Mode for decommissioning vSAN nodes
Leave the decommissioning mode on No data evacuation - this mode is the fastest method to shut down a vSAN cluster:
The virtual machines are shut down in a structured way and then all data will be synchronized on all affected hosts.
Definition of the vSAN Resync timeout
Unlike the default procedure, the vCenter becomes active after the virtual machine shut down and start synchronizing all records
within the cluster.
This post synchronization phase defines the critical phase of the shutdown procedure:
All datasets from the virtual machines must be in sync with mirrored data stored on other hosts.
As long as this synchronous system state is not reached, the Maintenance mode cannot be taken by any host.
Note:
This process is very dynamic and depends on the type of data that needs to be synchronized. You may have created several
new virtual machines and the synchronization time will only change marginally. However, it can also happen that you create a
virtual machine and thus radically increase the post-sync time. In other scenarios, the data within the virtual machine may grow
organically cause by the usage, which in turn affects the time required:
This value cannot be determined once during the first installation as a fixed value, it must be regularly checked for up-to-
datedness and adjusted if necessary.
The vCenter takes all the time needed for this process. Unfortunately, this relative amount of time is in direct contrast to a clearly
defined time window that can be provided by the UPS during an emergency power operation. You need to calculate a
sufficiently large time window to give the vCenter a time reserve in case of the calculated period is insufficient.
Defining maintenance mode for the vCenter.
This setting defines how much time the vCenter has to shut itself down after synchronizing data. If the vCenter runs as a virtual
machine within the vSAN, this point in time becomes interesting: After this time window, the hosts are put into maintenance
mode and the vCenter is switched off by its host.
To Next Page
Loading...
