Avago Technologies AcceleRAID 150 - Manual (Page 47)

Controller Start-up
Manual No. 775020 3-3
Enable 2 GByte or 8 GByte Drives
This setting affects how the BIOS reads the disk drives. Drive geometries
can be toggled between 2 GB and 8 GB. The default is 2 GB. When the drive
geometry setting is changed, the drive must be low level formatted.
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Caution
Changing this setting after data has been stored will
make the data unreadable. If you have already
configured your array and have stored data, you
should not change this setting.
The default BIOS geometry of the controller is set to 2 GB. This means that
the operating system through the BIOS can access only the first 2 GB of any
drive that has been configured on the controller. This is adequate in most
applications, since BIOS is used only to boot the operating system. However,
it does mean the operating system must be installed in the first 2 GB of the
capacity of the configured drive. Some operating systems are limited to a
2 GB boot partition.
If this is not adequate, the BIOS geometry can be changed to 8 GB, allowing
the operating system through the BIOS to access the first 8 GB of capacity.