NEC Storage Manager User Manual page 191

Chapter 8 Disk Array Configuration Setting (S100/S1100/S1200/S1300/S2100/S2200/S2300)
• Unused PD
Binds physical disks which have not configured the spare and RANK in the specified PD group. Does not
unbind spares and RANKs which have already been bound.
(C) RANK Information
The number of RANKs to bind is displayed.
The number of displays is automatically calculated depending on the disk array setting state as well as the set
values of spares and LDs.
(D) Setting Spare
Specifies the number of spares. The set value up to twice as many as the DE count can be specified. However,
the maximum value varies with the number of spare binding target physical disks. For example, if the DE count
is 2, the specifiable range is 0 to 4 and the initial value is 2. Since there are up to 8 spares per PD group, the
upper limit of the set value is 8 when the DE count is 4 or more.
Up to two spares can be created for a disk enclosure (DE).
DEs are physical components of the disk array on which physical disks are mounted.
When binding unused physical disks, the maximum value varies with the number of spares that have already been
bound.
(E) Setting RANK
Specifies the RAID type of the RANK to bind. This setup and the PD capacity determine the RANK capacity.
• High Reliability RAID1 (1+1):
• Standard RAID5 (4+P):
• Large Capacity RAID5 (6+P):
• Huge Capacity RAID5 (8+P):
Initial setting is set as "Standard RAID5 (4+P)".
Consisting of two PDs, the RANK capacity is equivalent to that of about
one PD.
Consisting of five PDs, the RANK capacity is equivalent to that of about
four PDs.
Consisting of seven PDs, the RANK capacity is the same as that of about
six PDs.
Consisting of nine PDs, the RANK capacity is the same as that of about
eight PDs.
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