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Draft Document for Review March 28, 2011 12:24 pm 7914Admin_Mappings.fm
Chapter 11. Administration - Mappings Tab
In this chapter, we describe the Mappings tab of the IBM System Storage DS Storage 
Manager. This tab is primarily used for assigning Logical Drives to host servers. It is done by 
storage partitioning (we name this process also âmappingâ). This functionality is also known 
as âLUN maskingâ. If a Logical Drive is mapped to a host, it is seen there as a LUN (Logical 
Unit Number).
In 3.3.7, âStorage partitioningâ on page 63 we explain the concept of storage partitioning. In 
this chapter we show practical examples of how to configure storage partitioning for SAS or 
FC connected hosts. If you need a specific procedure for iSCSI host attachment, see 
Chapter 13, âAdministration - iSCSIâ on page 317.
Because heterogeneous hosts can be attached to the DS3500 storage subsystem, you need 
to configure storage partitioning for two reasons:
ň° Each host operating system requires slightly different settings on the DS3500 storage 
subsystem. You need to tell the storage subsystem the host type to which is attached. 
ň° There is interference between the hosts if every host has access to every logical drive. By 
using storage partitioning (LUN masking), you ensure that each host or host group only 
has access to its assigned logical drives. 
You can have up to 256 LUNs assigned to a single storage partition, and a maximum of 256 
LUNs configured per DS3500 storage subsystem.