How To Create The Striping Array - NEC Express5800 Series Maintenance Manual

Chapter 2 Configuring and Upgrading the System
1.3

How to Create the Striping Array

The striping array (RAID0) is the RAID device that has the function to distribute the I/O request that was issued
to the striping array to each member.
This function improves the I/O performance and the data reading/writing speed for the striping array becomes
higher. In contrast to the RAID1 of the redundancy configuration, the disk capacity that can be used for the
striping array is as large as that for the total of members. The member installed to the striping array must be
separate hard disk drive. Otherwise, the I/O performance is not improved. Be careful of it.
If consisting only of the striping array and a failure occurs in any members, the entire array cannot be used and
the fault tolerance is lowered However, if the RAID1 device is used for the members of the array, the device
(RAID1+0) can be created so that it has the improved fault tolerance as well as the improved I/O performance.
Create the striping array using the ftdiskadm command. The following describes how to create the striping array
of md0 (the RAID1 device on Slot 2 and Slot 10) and md1 (the RAID1 device on Slot 3 and Slot 11).
1. Log in to the server as the root user. If you login with graphical mode, select [Others...] to login.
2. Execute "1 List RAID Arrays" of the ftdiskadm command, and check that the status of the RAID1 devices md0
and md1 is "DUPLEX" and Partition is blank (not mounted).
# ftdiskadm
(omitted)
Command: 1
[List RAID Arrays]
Name Partition
===============================================================================
< Mirroring Array (RAID1)
md0
md1
md123 /var/crash
md124 /boot/efi
md125 swap
md126 /boot
md127 /
Note
To take advantage of characteristics of the striping array effectively, 4 units or more of the
hard disk drive must be added.

Tips For the striping array, a set of the RAID1 device that has been already created must be
used. At this time, it is recommended to back up the user data as required since the
data written in the RAID1 device is deleted.

To take full advantage of the characteristics of the striping array, it is recommended
that capacities of each RAID1 device should be even.

Tips For the slot number, refer to "1.1 Available Disk Configuration" in this chapter.

The ext4 file system can be created by default. The file system can be changed with
the commands such as mkfs.
Status
>
DUPLEX
DUPLEX
DUPLEX
DUPLEX
DUPLEX
DUPLEX
DUPLEX
Express5800/R320e-E4, R320e-M4 Maintenance Guide (Linux)
Member
(2)104002-part1 (10)114002-part1
(3)104003-part1 (11)114003-part1
(1)104001-part2 (9)114001-part2
(1)104001-part5 (9)114001-part5
(1)104001-part3 (9)114001-part3
(1)104001-part4 (9)114001-part4
(1)104001-part1 (9)114001-part1
1. Hard Disk Drive Duplexing
93