Owner's manual

Grid Center 4.11 Administrator’s Guide Allocation • 41
Allocation
Grid Center utilizes the concepts of I/Port groups and Blade groups for the purpose of
mapping, or allocating, I/Ports to Blades. A group can contain a single I/Port or Blade,
or many. Allocation defines the allowable connections (mappings) between the I/Port
groups and Blade groups.
Allocation allows administrators to allocate dynamic or static mappings between
groups of Blades and I/Ports. Allocation consists of these tasks:
• Create groups
• Add Blades and I/Ports to the groups
• Assign Blades and I/Ports between the groups
• Create shared mappings if desired
After they are created, allocations can be easily modified to allow for changing
network needs and use. Three types of allocations are possible:
• Dedicated – connects the I/Port to the same assigned Blade each time.
• Shared – connects an I/Port to any available Blade in a group, based on the least
load average.
• Spare – allows switching an I/Port to any available spare Blade in the event of a
Blade failure. Typically, Spared Blades do not have any active connections.
These Blades are, as the name suggests, reserved for use only when necessary
as a replacement. More than one Spare Blade group can be created.
When a Blade group is designated as a Dedicated group, I/Ports can connect only to
a specified Blade in that group. This is a static mapping. It does not change between
sessions.
When a Blade group is designated as a Shared group, I/Ports can connect to any
Blade in the group, based on the least-load average algorithm, which monitors
system usage and automatically assigns I/Ports to the Blade in the group that has the
least load when the connection is attempted. This is a dynamic mapping in the sense
that it may be different at the start of any given session.