Using auto-carving for multi lun support – AMCC 3WARE 720-0138-00 User Manual

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Chapter 4. Configuring Your Controller

3ware Serial ATA RAID Controller User Guide for the Power Mac G5

To enable Auto Rebuild through 3DM

Choose

Management > Controller Settings

from the menu bar in 3DM.

In the Other Controller Settings section at the bottom of the screen, select
the

Enabled

option for

Auto Rebuild

The page refreshes, and a message at the top confirms the change you
have made.

Using Auto-Carving for Multi LUN Support

When the Auto-Carving policy is on, any unit larger than a specified size
(known as the carve size) is created as multiple volumes that can be addressed
by the operating system as separate volumes. These chunks are sometimes
known as multiple LUNs (logical units). However, throughout the 3ware
documentation, they are referred to as volumes.

For example, using the default carve size of 2 TB, if the unit is 2.5 TB then it
will contain two volumes, with the first volume containing 2TB and the
second volume containing 0.5 TB. If the unit is 5.0 TB then it will contain 3
volumes, with the first two volumes containing 2 TB each and the last volume
containing 1 TB.

Each volume can be treated as an individual disk with its own file system. The
default carve size is 2 TB; you can change this to a setting in the range of
1 TB to 2 TB (1024 MB to 2048 MB). 3ware firmware supports a maximum
of 8 volumes per controller, up to a total of 16 TB.

If you are migrating a unit to a size that is larger than the carve size and auto-
carving is on, multiple volumes will be created.

You must turn on the Auto-Carving policy before creating the unit. Units
created with this policy turned off will not be affected by a change to the
policy. If the policy is turned off later, units that have been carved into
volumes will retain their individual volumes; existing data is not affected.

To use auto-carving

Enable the auto-carving feature.

In 3DM, enable Auto-Carving at the bottom of the

Management >

Controller Settings

page.

Note:

Using auto-carving can have an impact on performance.