NEC EXP200, User Manual

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10-6 Internal Cabling Diagrams
Connection of Disk Array Controller N8103-80 (SCSI)
If SCSI hard disk drives are installed, the disk array controller (SCSI) can be connected to the server.
The internal hard disk drives can be subject to the disk array configuration. The supported RAID
configuration includes RAID0 (striping), RAID1 (mirroring), and RAID5 (st parity). Hard
disk drives having a different interface cannot be installed together. In addition, the disk array
controller cannot be connected to disk expansion unit.
The SCSI hard disk drives can be hot-swapped by using the HDD device bay conversion kit
(N8154-02). In this case, the device bay conversion kit (K8154-03) is also required.
IMPORTANT:
If N8154-02 is used, 3.5-inch device bay cannot
contain any hard disk drive.
„
RAID0 (striping)
Stores data on two hard disk drives by dividing it (striping). Both hard disk drives can be
accessed at the same time. This improves disk access performance compared with using a
single hard disk.
IMPORTANT:
„
RAID0 does not have data redundancy. When a hard disk drive
failure occurs, data cannot be restored.
„
Logical capacity of the array becomes a multiple of the connected
hard disk drive.
„
RAID1 (mirroring)
Stores the data being saved to one hard disk dive to another hard disk drive. This method
is called "mirroring." When storing data onto one hard disk drive, the same data is
simultaneously stored onto another hard disk drive. When a hard disk drive becomes
faulty, the one with the same data can be used. This provides operation without the system
going down.
IMPORTANT:
„
RAID1 reads or writes data to/from the two hard disk drives at the
same time. The disk access performance is lower than the single
disk.
„
Logical capacity of the array is equal to one hard disk drive
connected.
„
RAID5 (st parity)
Stores data onto four hard disk drives by dividing it (striping) in the same way as RAID0.
With RAID5, parity (redundant data) is also divided and stored on four hard disk drives.
Even if one of the configured hard disk drives becomes faulty, data can be used without
any problem.