Enabling The Enhanced Remote Mirroring Feature; Activating The Enhanced Remote Mirroring Feature - IBM System Storage DS3000 Programming Manual

Enabling the Enhanced Remote Mirroring Feature

The first step in creating a remote mirror is to make sure that the Enhanced Remote Mirroring feature is
enabled on both storage subsystems. Because Enhanced Remote Mirroring is a premium feature, you
need a Feature Key file to enable the feature. The command for enabling the Feature Key file is as
follows:
enable storageSubsystem feature file="filename"
where the file parameter is the complete file path and file name of a valid Feature Key file. Enclose the
file path and the file name in double quotation marks (" "). Valid file names for Feature Key files end
with a .key extension.

Activating the Enhanced Remote Mirroring Feature

Activating the Enhanced Remote Mirroring feature prepares the storage subsystems to create and
configure mirror relationships. After you activate the feature, the secondary ports for each controller are
reserved and dedicated to remote mirror use. In addition, a mirror repository logical drive is
automatically created for each controller in the storage subsystem. As part of the activation process, you
can decide where the mirror repository logical drives will reside, free capacity on an existing subsystem
or in a newly created subsystem, and the RAID level for the mirror repository logical drives.
The free capacity that you select for the mirror repository logical drive must have a total of 256 MB of
capacity available. Two mirror repository logical drives are created on this capacity, one for each
controller. If you enter a value for the repository storage space that is too small for the mirror repository
logical drives, the firmware returns an error message that gives the amount of space needed for the
mirror repository logical drives. The command does not try to activate the Enhanced Remote Mirroring
feature. You can re-enter the command using the value from the error message for the repository storage
space value.
The RAID level that you choose for the mirror repository logical drive has these constraints:
RAID 0 – You cannot use RAID 0.
v
RAID 1 – The number of drives must be an even number. If you select an odd number of drives, the
v
controller firmware returns an error.
RAID 3 or RAID 5 – You must have a minimum of three disk drives in the subsystem.
v
RAID 6 – You must have a minimum of five disk drives in the subsystem.
v
To activate the Enhanced Remote Mirroring feature, use this command:
activate storageSubsystem feature=remoteMirror
The activate storageSubsystem feature=remoteMirror command provides three methods for defining
the disk drives for your mirror repository logical drive:
v You define each disk drive for the mirror repository logical drive by its enclosure ID and its slot ID.
v You define an subsystem in which the mirror repository logical drive resides. You can optionally define
the capacity of the mirror repository logical drive.
v You define the number of disk drives, but not specific disk drives, for the mirror repository logical
drive.
Activating the Enhanced Remote Mirroring Feature with User-Assigned Disk Drives
Activating the Enhanced Remote Mirroring feature by assigning the disk drives provides flexibility in
defining your configuration by letting you choose from the available disk drives in your storage
subsystem. Choosing the disk drives for your remote mirror automatically creates a new subsystem. You
can specify which disk drives to use and the RAID level for the new subsystem.
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IBM System Storage DS3000, DS4000, and DS5000: Command Line Interface and Script Commands Programming Guide