Node retirement¶
Overview¶
Retiring nodes is a natural part of a server’s life cycle, for instance when the end of the warranty is reached and the physical space is needed for new deliveries to install replacement capacity.
However, depending on the type of the deployment, removing nodes from service can be a full workflow by itself as it may include steps like moving applications to other hosts, cleaning sensitive data from disks or the BMC, or tracking the dismantling of servers from their racks.
Ironic provides some means to support such workflows by allowing
to tag nodes as retired
which will prevent any further
scheduling of instances, but will still allow for other operations,
such as cleaning, to happen (this marks an important difference to
nodes which have the maintenance
flag set).
How to use¶
When it is known that a node shall be retired, set the retired
flag on the node with:
baremetal node set --retired node-001
This can be done irrespective of the state the node is in, so in
particular while the node is active
.
Note
An exception are nodes which are in available
. For backwards
compatibility reasons, these nodes need to be moved to
manageable
first. Trying to set the retired
flag for
available
nodes will result in an error.
Optionally, a reason can be specified when a node is retired, e.g.:
baremetal node set --retired node-001 \
--retired-reason "End of warranty for delivery abc123"
Upon instance deletion, an active
node with the retired
flag
set will not move to available
, but to manageable
. The node
will hence not be eligible for scheduling of new instances.
Equally, nodes with retired
set to True cannot move from manageable
to available
: the provide
verb is blocked. This is to prevent
accidental re-use of nodes tagged for removal from the fleet. In order
to move these nodes to available
none the less, the retired
field
needs to be removed first. This can be done via:
baremetal node unset --retired node-001
In order to facilitate the identification of nodes marked for retirement,
e.g. by other teams, ironic also allows to list all nodes which have the
retired
flag set:
baremetal node list --retired