|
Use Larger Sector Sizes
One way to break the 2.19 TB
boundary would be to use a larger sector
size and keep the number of addressable
blocks the same. By using sector sizes
of 4096 (4K) bytes this would allow for
systems to address a maximum capacity of
232 x 4096 bytes or 17.59 TB.
Unfortunately, WD has determined through
testing that is not feasible at this
time due to many application
incompatibilities with devices using
sector sizes above 512 bytes. However,
hard drive manufacturers are working
with industry partners to implement
larger native sector sizes in the
future. WD has transitioned to using
sector sizes of 4096 bytes or a 4 KB
physical sector size on some hard drive
models; this is referred to Advanced
Format (AF) technology. Although the
drive may be using a sector size of 4096
bytes to store data on the media, it
reports and emulates a disk using 512
bytes (512e) to avoid application
incompatibilities.
Use GPT Instead of MBR
The solution adopted by the industry
is to use GUID Partition Tables,
otherwise known as GPT, instead of
Master Boot Record (MBR) partition
tables. UEFI is a community effort by
many companies in the computer industry
to modernize the booting process. This
partitioning method provides for up to
18 Exabyte (264) of Logical Block
Addressing. UEFI capable systems are
already shipping, and many more are in
preparation. Booting a current Windows
operating system from a drive larger
than 2.19 TB requires that the system
have UEFI support, a 64-bit version of
the OS and will create and use GPT
partitions. The UEFI specification
defines a new model for the interface
between operating systems and platform
firmware. The interface consists of data
tables that contain platform-related
information, plus boot and runtime
service calls that are available to the
operating system and its loader.
Together, these provide a standard
environment for booting an operating
system and running pre-boot
applications.
Implement WD’s Interim Solutions for
Implementing Large Capacity Drives
Existing legacy (non-UEFI) BIOS
motherboards and GPT-ready operating
systems such as Windows Vista or Windows
7, combined with the appropriate storage
class drivers, can use drives larger
than 2.19 TB as secondary storage; but
there are a number of host bus adapter (HBA)
and chipset vendors that do not
currently offer drivers that support
drives larger than 2.19 TB. To provide a
solution for these types of
compatibility issues, WD is bundling
large capacity WD Caviar® Green™ 2.5 TB
and 3 TB drives with an AHCI-compliant
HBA that, once installed, allows the
operating system to use a known driver
to correctly support large capacity
drives. This bundle provides a
short-term solution until the time when
updated storage drivers and system
software with support for large capacity
drives become available.
Illustrative Example: Should an end
user decide to add a secondary drive to
an existing desktop computer system that
incorporates a chipset such as an
Intel-based chipset on a legacy (non-UEFI)
motherboard running an operating system
such as Windows, the 3rd party storage
class driver may not properly support a
drive larger than 2.19 TB. If the large
capacity drive is attached directly to
the native motherboard SATA controller,
the 3rd party driver may attach to the
drive and the driver will not recognize
the drive’s full capacity, resulting in
an incompatibility issue. An attempt to
uninstall the driver could render the
whole system inoperable. However, when
the drive is connected to the WD-bundled
HBA, a Windows operating system would
load native AHCI drivers that would
correctly support large capacity drives
and allow normal partitioning and use of
the drive.
The example above is only one of many
cases where the WD bundled HBA will
solve the problem due to an incompatible
driver.
How You Can Take Advantage of Large
Capacity Drives
WD provides many options that you
can use to take advantage of large
capacity drives, even on current
computer system configurations with
today’s technologies.
·
Implement the WD bundle (large capacity
WD Caviar Green 2.5 TB and 3 TB drives
with an AHCI-compliant HBA) to
allow your system’s operating system to use a known driver to correctly
support large capacity drives
·
Implementing a large capacity WD drive
as the system start up drive will
require a system with UEFI support and
will
use GPT partitions. Windows will require a 64 bit version of the
operating system.
·
Implementing a large capacity WD drive
in legacy systems will enable using the
large capacity drive as secondary
storage and will use GPT partitions.
·
Review the considerations for
Windows-based operating systems above to
help determine what options are
available for implementing large capacity drives on your current systems,
and to help you plan future operating
system and computer system purchasing plans.
Contact your WD representative for
additional information and assistance
with implementing large capacity drives
or visit our website at
http://products.wdc.com/largecapacitydrives. |
