Disable the HA cluster before you apply software upgrades, patches, or hotfixes that
include database updates.
SMS clients use an IP address or a hostname to connect to an SMS server. When an SMS
client first connects to an SMS HA cluster, it obtains and caches the IP addresses
of each cluster node. When you disable the cluster, you break the cluster into separate,
independent systems with identical configurations. Ensure one of the SMS servers is
rendered inaccessible to SMS clients and devices so that the two servers do not compete
with each other. To avoid device management conflicts after you disable SMS HA, you
can either power off the SMS that is not being used or perform a factory reset.
Because only one SMS can manage a device, the device always records the IP address
and the certificate of the SMS in the HA cluster that manages it. This also prevents
another SMS from taking control of the same device.
Under normal HA failover conditions, the certificate from the active SMS is copied
to the passive SMS and used to manage the devices. If the cluster fails-over or is
swapped, then the devices are still seamlessly managed with the same certificate.
If the original passive SMS server becomes the active SMS server and you disable
HA, then the SMS displays a dialog with two list panels.
- The left panel identifies devices that will continue to be managed by the currently active (original secondary) SMS.
- The right panel identifies devices that will be unmanaged by the currently active SMS. The devices in this right panel will be managed by the currently passive (original primary) SMS unless you unmanage them and remanage them on the currently active SMS.