Synology DiskStation DS216j Quick Installation Manual page 49

RAID Group Types
Your Synology NAS supports the following RAID Groups types:

RAID Group for Single Volume or iSCSI LUN (Block-Level)
 Allocates all available capacity to a single volume or iSCSI LUN (Block-Level).
 Provides better performance but less storage management flexibility.
 Allows creation of multiple iSCSI LUNs (Regular File) on volumes.
 Supports a maximum of one RAID Array.

RAID Group for Multiple Volumes or iSCSI LUNs (Block-Level)
 Supports creating multiple volumes or iSCSI LUNs (Block-Level) on a RAID Group.
 Provides better storage management flexibility.
 Allows creation of multiple iSCSI LUNs (Regular File) on volumes.
 Supports combining multiple RAID Arrays under a RAID Group (when configured as RAID 5 or RAID 6).
 The maximum volume size that can be allocated is 200TB (when configured as RAID 5 or RAID 6, with at
least 32GB RAM installed).
RAID Types
Depending on the number of available hard disks, you can create RAID Groups using several different RAID
types. Different RAID types provide different levels of performance, data protection, and storage features.
Synology NAS supports the following RAID types
RAID Type HDD #
Basic 1
≧ 1
JBOD
RAID 0 2-12
RAID 1 2-4
3-12 per
RAID 5
RAID Array
4-12 per
RAID 6
RAID Array
4-12 per
RAID Array
RAID 10
(even
number)
---------
1
Synology Hybrid RAID (SHR) is not supported on models with RAID Groups.
33 Chapter 6: Manage Storage Space with RAID Groups10F
1
:
Allowed
Failed HDD #
0 Creates a storage space with one hard disk.
Combines multiple hard disks into a single, large
0
storage space.
RAID 0 offers Striping, a process of dividing
data into blocks and spreading the data blocks
0
across several hard drives, but without safety
measures.
Writes a mirrored copy of data to each hard
(HDD #) - 1 drive, providing data redundancy and protection
as long as one hard disk is operating normally.
Stripes both data and parity information across
all member disks, providing data redundancy. If
one hard disk fails, the system may be rebuilt
1 HDD within
using parity data from other member hard disks
each RAID
Array
Supports combining multiple RAID Arrays when
created on a RAID Group for Multiple Volumes
or iSCSI LUNs (Block-Level)
RAID 6 provides extra data protection. It uses
parity mode to store redundant data on space
equal to the size of two disks for later data
2 HDD within
recovery.
each RAID
Array
Supports combining multiple RAID Arrays when
created on a RAID Group for Multiple Volumes
or iSCSI LUNs (Block-Level)
1 HDD within Provides the performance of RAID 0 and data
each RAID 1 protection level of RAID 1. RAID 10 combines
group / Half of two hard drives into a RAID 1 group, and
the total HDD combines all the groups with RAID 0.
Synology NAS User's Guide
Description
Based on DSM 6.1
Capacity
1 x (HDD size)
Sum of all HDD
sizes
Sum of all HDD
sizes
Smallest HDD
size
Total capacity of
combined RAID
Arrays.
RAID Array
capacity = (HDD
# - 1) x (Capacity
of smallest
HDD).
Total capacity of
combined RAID
Arrays.
RAID Array
capacity =
(HDD# - 2) x
(Capacity of
smallest HDD)
(HDD # / 2) x
(Smallest HDD
size)