Table9-1 Typesof m aintenance for the crossbar unit
Configuration Active/hot Active/cold Inactive/hot Inactive/cold Systemstopped
Building block configuration
Unsupported Supported (*) Unsupported Supported Supported
*:It is necessary to use dynami c reconfiguration (DR) to disconnect a chassis requiring mainten ance from the physical partition.
Table9-2 Maintenanceflow
Detailsof update process Replacement
1 Preparation 9.3
2 Removingthe crossbar units 9.4
3 Installingthe crossbar unit 9.5
4 Restoringthe system 9.6
Caution- To completely sh ut down the system, all the power cords must be
removed. If the power cords are not removed, an electrical failure may occur.

9.2.2 Maintenance flow

Table9-2 lists the sequence of the maintenance procedure for the crossbar units.
9.3 Enabling the Removal of a Crossbar
Unit
Thissectio n describes preparation that must be completed prior to removing a
crossbarunit. The procedure for the preparation varies depending on the maintenance
type,as fo llows:
■Active/Coldmaintenance
■Inactive/Cold maintenance
■System-stopped maintenance
Chapter9 Maintainingthe Crossbar Units 181