QNAP TVS-472XT 4-Bay NAS Enclosure User Manual
Page 57
QTS displays all available RAID types and automatically selects the most optimized RAID type.
Number of disks
Supported RAID Types
Default RAID Type
One
Single
Single
Two
JBOD, RAID 0, RAID 1
RAID 1
Three
JBOD, RAID 0, RAID 5
RAID 5
Four
JBOD, RAID 0, RAID 5, RAID 6, RAID 10
RAID 5
Five
JBOD, RAID 0, RAID 5, RAID 6
RAID 6
Six or more
JBOD, RAID 0, RAID 5, RAID 6, RAID 10, RAID 50
Note
RAID 10 requires an even number of disks.
RAID 6
Eight or more
JBOD, RAID 0, RAID 5, RAID 6, RAID 10, RAID 50, RAID 60 RAID 6
Tip
Use the default RAID type if you are unsure of which option to choose.
.
7. Optional: Select the disk that will be used as a hot spare for this RAID group.
The designated hot spare automatically replaces any disk in the RAID group that fails.
For RAID 50 or RAID 60, a spare disk must be configured later. You should configure a global spare disk
so that all subgroups share the same spare disk.
8. Optional: Select the number of RAID 50 or RAID 60 subgroups.
The selected disks are divided evenly into the specified number of RAID 5 or 6 groups.
• A higher number of subgroups results in faster RAID rebuilding, increased disk failure tolerance,
and better performance if all the disks are SSDs.
• A lower number of subgroups results in more storage capacity, and better performance if all the
disks are HDDs.
Warning
If a RAID group is divided unevenly, the excess space becomes unavailable. For example, 10
disks divided into 3 subgroups of 3 disks, 3 disks, and 4 disks will provide only 9 disks of storage
capacity.
9. Click Next.
10. Optional: Configure SSD over-provisioning.
Over-provisioning reserves a percentage of SSD storage space on each disk in the RAID group to
improve write performance and extend the disk's lifespan. You can decrease the amount of space
reserved for over-provisioning after QTS has created the RAID group.
Tip
To determine the optimal amount of over-provisioning for your SSDs, download and run SSD
Profiling Tool from App Center.
11. Optional: Configure the alert threshold.
QTS issues a warning notification when the percentage of used pool space is equal to or above the
specified threshold.
12. Click Next.
13. Click Create.
QTS 4.4.x User Guide
Storage & Snapshots
56