IBM N Series, Implementation Manual

Page: 31 / 105

Chapter 2: Planning for Using Disk S helves with a Gateway 17
licensing You need only a gateway license. No special license is required to
support a specific storage type on a gateway.
limits for disks and array LUNs When N series storage system disk limits and gateway array LUN
limits differ, the total limit of all the disks plus all array LUNs must
be less than or the same as the gateway platform LUN limit. See
“
Limits on a gateway using both disks and array LUNs ” on page 28.
MetroCluster Not supported on the gateway if native disk shelves are installed on
it.
paths to storage
◆
For stand-alone and HA
pairs, you can establish one
or two paths between the
gateway controller and the
disk shelf. Two paths are
required for redundancy.
◆
For an HA pair, you must
use the Multipath Storage
feature if you want
redundant connections. See
Appendix B, “
Setting up
and Managing Multipath
Storage
,” on page 65 for
details about this feature,
including restrictions.
The requirements are as follows:
◆
Two redundant paths are
required between the
gateway and each array
LUN.
◆
More than two paths to an
array LUN is not supported.
RAID RAID-DP and RAID4 are
supported on native disks. The gateway uses RAID0 and
relies on the RAID protection
that the storage arrays provide
through the various RAID levels
on the storage arrays.
RAID4 and RAID-DP are not
supported for array LUNs
Data ONTAP feature or
function
Native disk shelves Array LUNs