9
(3) Selection of Quantity/Capacity of Disk Drive
The logical disk capacity you can configure varies depending on the type (I/F, capacity) of disk drive
and the level of RAID.
Besides, necessary logical disk capacity varies depending on the functions you use (e.g.
Snapshot/Replication function).
To determine the necessary number of disk drive, it is necessary to determine the type (I/F,
capacity, rotation number) of disk drive and the level of RAID according to the usage of data and
calculate the necessary logical disk capacity by referring to the following information.
Beside, you are required to mount at least 3 or more disk drives per node, regardless of the type
(SAS/SATA) of disk drive.
Meanwhile, for support RAID type, refer to “Support RAID” mentioned below.
DE#00
(Notes)
Snapshot
Snapshot reserved area is necessary for creating snapshot to a master volume.
Replication
In case of using replication function, using Storage System Information Retention Function* to
create the Storage System Volume is strongly recommended.
The capacity of storage system volume is 8.9GB (1GB=1000
3
Byte)/8.3 GB (1GB=1024
3
Byte).
By turning the power off according to the normal procedure, Storage System Data (difference
map etc.) will be backed up into the Storage System Volume. Without the Storage System
Volume, it retains the storage system information in cache memory within a battery backup
time but the lifetime of battery will shorten. In case not to use the Storage System Volume 24
hours power distribution is recommended.
*Storage System Information Retention Function is the function to back up storage system
data such as difference map of Master Volume (MV) and Replication Volume (RV) to a disk
drive.
(3-1) Selection of Capacity/Quantity of SAS/SATA Disk Drive
Select necessary number of SAS disk drive.
Product code
Product name
Product outline
Average
seek time
(R/W)
Physical
capacity
(GB)
*1
*2
NF5021-SM624E SAS Disk Drive (15krpm/147GB)
147GB
15,000rpm
3.5ms/4.0ms 142.9 133.1
NF5021-SM625E SAS Disk Drive (15krpm/300GB)
300GB
15,000rpm
3.5ms/4.0ms 288.0 268.2
NF5021-SM627E SAS Disk Drive (15krpm/450GB)
450GB
15,000rpm
3.5ms/4.0ms 440.2 410.0
NF5023-SM728E SAS Disk Drive (15krpm/600GB)
600GB
15,000rpm
3.5ms/4.0ms 576.0 536.4
*1: Calculated figures based on 1GB=1,000,000,000B
*2: Calculated figures based on 1GB=1,073,741,824B(1,024
3
B)
#00 #01 #02 #03
#04 #05 #06 #07
#08 #09 #0A #0B
* Make sure to mount disk drives into slots
#00, #01 and #02.