Raid Types - ZyXEL Communications NAS326 User Manual

• External volumes (built on the external storage devices attached to the NAS)
Internal Volumes
Table 9 Internal Volumes
OPTION DESCRIPTION
Volume Allocates all the available space to the volume.
Provides better performance.
Volume on Disk Allows you to create multiple volumes on a disk group.
Group
Allows you to customize the size of a volume.

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.
Table 10 RAID Types
RAID NO. OF
TYPE HDD ALLOWED TO FAIL
Basic 1
JBOD 2-4
RAID 0 2-4
RAID 1 2-4 (No. of HDD) -1
RAID 5 3-4
RAID 6 4
RAID 10 4 1 HDD in each RAID
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.
Chapter 5 Storage Manager
NO. OF HDD
0 Use Basic with one disk. It has no fault tolerance.
0 Use JBOD with two or more disks for maximum
capacity. This is just a collection of disks with no
fault tolerance.
0 Use RAID 0 with two or four disks for maximum
speed and no fault tolerance.
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.
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.
2 Use RAID 6 with four disks for more data
protection in case of disk failure.
Use RAID 10 with four disks to get better
1 group
performance than RAID 6, with slightly less data
protection.
NAS Series User's Guide
44
DESCRIPTION CAPACITY
1 x (HDD size)
sum of HDD sizes
sum of HDD sizes
Smallest HDD size
(No. of HDD – 1) x
(smallest HDD size)
(No. of HDD – 2) x
(smallest HDD size)
(No. of HDD / 2) x
(smallest HDD size)