ZyXEL Communications NAS540, User Manual

Page: 50 / 372

Chapter 8 Storage Manager
Cloud Storage User’s Guide
50
Internal Volumes
RAID Types
The following table describes RAID types.
Note: RAID 5, RAID 6, RAID 10, and the hot spare option apply to 4-bay NAS devices.
Repair Volumes or Disk Groups
If a hard disk in a RAID 1 with a hot spare or a RAID 5 with a hot spare fails, the NAS automatically
uses the hot spare to re-build the volume or disk group. Later you can replace the failed hard disk
and add the new disk as a hot spare.
A hard disk failure in a RAID 1, RAID 5, RAID 6, or RAID 10 degrades the volume or disk group.
Replace the failed disk and use the
Internal Storage screen’s Repair link to repair the volume.
Table 7
Internal Volumes
OPTION DESCRIPTION
Volume Allocates all the available space to the volume.
Provides better performance.
Volume on Disk
Group Allows you to create multiple volumes on a disk group.
Allows you to customize the size of a volume.
Table 8
RAID Types
RAID
TYPE
NO. OF
HDD
NO. OF HDD
ALLOWED TO
FAIL
DESCRIPTION CAPACITY
Basic 1 0 Use Basic with one disk. It has no fault
tolerance.
1 x (HDD size)
JBOD 2-4 0 Use JBOD with two or more disks for
maximum capacity. This is just a collection of
disks with no fault tolerance.
sum of HDD sizes
RAID 0 2-4 0 Use RAID 0 with two or four disks for
maximum speed and no fault tolerance.
sum of HDD sizes
RAID 1 2-4 (No. of HDD) -1 Use RAID 1 to create an exact copy of data
on one disk to a second disk. Use this with
two to four disks to mirror primary data to
another disk(s) with high performance.
You can add a hot spare to a 2-disk RAID 1.
Smallest HDD size
RAID 5 3-4 1 Use RAID 5 with three or four disks to
balance performance and hard disk capacity
usage with data protection in case of disk
failure.
You can add a hot spare to a 3-disk RAID 5.
(No. of HDD – 1) x
(smallest HDD
size)
RAID 6 4 2 Use RAID 6 with four disks for more data
protection in case of disk failure.
(No. of HDD – 2) x
(smallest HDD
size)
RAID 10 4 1 HDD in each
RAID 1 group
Use RAID 10 with four disks to get better
performance than RAID 6, with slightly less
data protection.
(No. of HDD / 2) x
(smallest HDD
size)