SAS - Zone configuration

From SAS2r16 Spec. page 120

Zoning expander devices implement a lock to coordinate zoning configuration by zone manager(s).
There are four steps in the zone configuration process:

1) lock

2) load

3) activate
The activate step:
a) copies the zoning expander shadow register values to the current values
b) saves the zoning expander shadow values, if saving was requested.

4) unlock
The unlock step ensures that:
a) the active zone manager unlocks the locked zoning expander devices; or
b) if the zone manager fails, then the zone lock inactivity timer expires, and the
zoning expander devices unlock.

The management device server in a zoning expander device only accepts
1-SMP zone configuration function requests
The SMP zone configuration functions are:
a) SMP CONFIGURE ZONE PHY INFORMATION
b) SMP CONFIGURE ZONE PERMISSION TABLE
c) SMP ENABLE DISABLE ZONING
2-SMP ZONE ACTIVATE requests
3-SMP ZONE UNLOCK requests
while it is locked

It only accepts SMP zone configuration function requests from the zone manager that locked the zoning expander device (i.e., the active zone manager).

SMP zone configuration functions change zoning expander shadow values.

When changes are complete, the zone manager activates the changes and
the zoning expander device sets the zoning expander current values equal to the zoning expander shadow values.

The zone manager then unlocks the zoning expander devices.

For a ZPSDS to function correctly, all zoning expander devices within the ZPSDS are required to have identical values in their zone permission tables.

To change zone permission tables, a zone manager device locks all zoning expander devices in a ZPSDS.

To change zone phy information, a zone manager locks only the zoning expander devices containing the phys to be changed.

When a zoning expander device with zoning disabled is being added to a ZPSDS or two or more ZPSDSes are being merged, the zone manager locks all of the zoning expander devices that are to be included in the final ZPSDS.

The zone manager configures the zone phy information in each zoning expander device
(e.g., sets the REQUESTED INSIDE ZPSDS bit to one for phys inside the final ZPSDS) and configures all of the zone permission tables to be identical.

If the zone lock inactivity timer expires, then the zoning expander device performs the unlock step.
The zoning expander device is unlocked and the zoning expander shadow values are not activated.