Toshiba M400 Personal Computer User Manual


 
User’s Manual G-3
TOSHIBA RAID
Boot menu
When 2 hard disk drives are connected, it is possible to select which
hard disk drive to boot from in the boot menu. However, if a RAID
configuration is used, the 2 hard disk drives are recognized as 1 drive
and there is no change in the boot configuration no matter which hard
disk drive is selected.
When using a RAID-1 (mirroring) configuration, the additional hard disk
drive’s capacity must be equal to or more than the capacity of the
existing hard disk drive.
The hard disk drives used in the RAID configuration should not be
removed and used in other computers.
When using the RAID-1 (mirroring) configuration, the OS recognizes
the lesser capacity of the 2 hard disk drives.
For example, if a 60 GB and an 80 GB hard disk drive are used in the
mirroring configuration, the OS will recognize the capacity as a 60 GB
hard disk drive.
The additional 20 GB capacity (over the 60 GB hard disk drive) of the
80 GB hard disk drive cannot be used.
The size seen by the OS is twice that of the smaller of the two HDD
units in the RAID configuration. For example, when RAID-0 is
configured using one 40GB and one 60GB HDD, it is seen by the OS
as 80GB. The remaining 20GB on the 60GB HDD will be assigned to a
logical drive.
All data on both disks will be lost, even if only one of the two disk drives
fails.
If a hard disk drive had been replaced, execute the rebuild command
and rebuild the RAID-1 (mirroring) configuration.
Implementing the media checking schedule
Media checks should be carried out regularly to ensure even more
stable operation of the RAID configuration and to make it easier for
maintenance and repair measures to be carried out in case of hard disk
drive failures.
For RAID-1 with data redundancy, if a hard disk drive failure occurs,
the hard disk drive is replaced and its data reconstructed from the other
hard disk drive which did not fail.
If there are bad blocks, etc., in the hard disk drive that did not fail, it is
possible that portion of data might not be recovered and system down
might occur.
An effective way to ensure that such situations do not happen is to
carry out RAID-1 media checks regularly.
The TOSHIBA RAID utility is set as default to carry out media checks
every month on the third Wednesday from noon.