Frequently Asked Question
Storage: QNAP Turbo NAS Choose a RAID Type
Last Updated 3 years ago
Choose a RAID TypeRAID (Redundant Array of Independent Disks) is a data storage technology that allows multiple drives to be combined into a single storage space. There are different types of RAID, each providing different levels of performance, storage capacity, and reliability.
This article provides a brief overview of RAID types supported by Synology NAS, including implementation requirements as well as advantages and disadvantages.
This table provides a brief overview of different RAID types supported by QNAP Turbo NAS, including storage capacity, the minimum number of drives required for the RAID type, and the number of drive failures that can be tolerated before data loss occurs.
Support RAID Types
| Volume Type || Number of HDD || Tolerable Drive Failures || Description || Volume Capacity |
| Basic || 1 || 0 || || 1 x (HDD size) |
| JBOD || ≧1 || 0 || || Sum of all HDD sizes |
| RAID 0 || ≧2 || 0 || || Sum of all HDD sizes |
| RAID 1 || 2 || 1 || || Smallest HDD size |
| 3 || 2 |
| 4 || 3 |
| RAID 5 || ≧3 || 1 || || (N – 1) x (Smallest HDD size) |
| RAID 6 || ≧4 || 2 || || (N – 2) x (Smallest HDD size) |
| RAID 10 || ≧4 |
| Half of the total HDD || || (N / 2) x (Smallest HDD size) |
- RAID types except for "Basic" are only available on certain models depending on the number of drive slots and number of installed drives.
- "N" represents the total number of drives within the volume.
RAID 0RAID 0 combines two or more drives to increase performance and capacity, but provides no fault tolerance. A single drive failure will result in the loss of all data on the array. RAID 0 is useful for non-critical systems where a high price/performance balance is required.
RAID 1RAID 1 is most often implemented with two drives. Data on the drives are mirrored, providing fault tolerance in case of drive failure. Read performance is increased while write performance will be similar to a single drive. A single drive failure can be sustained without data loss. RAID 1 is often used when fault tolerance is key, while space and performance are not critical requirements.
RAID 5RAID 5 provides fault tolerance and increased read performance. A minimum of three drives is required. RAID 5 can sustain the loss of a single drive. In the event of a drive failure, data from the failed drive is reconstructed from parity striped across the remaining drives. As a result, both read and write performance is severely impacted while a RAID 5 array is in a degraded state. RAID 5 is ideal when space and cost are more important than performance.
RAID 6RAID 6 is similar to RAID 5, except it provides another layer of striping and can sustain two drive failures. A minimum of four drives is required. The performance of RAID 6 is lower than that of RAID 5 due to this additional fault tolerance. RAID 6 becomes attractive when space and cost are important and sustaining multiple drive failures is required.
RAID 10RAID 10 combines the benefits of RAID 1 and RAID 0. Read and write performance is increased, but only half of the total space is available for data storage. Four or more drives are required making the cost relatively high, but the performance is great while providing fault tolerance at the same time. In fact, a RAID 10 can sustain multiple drive failures -- provided the failures are not within the same sub group. RAID 10 is ideal for applications with a high input/output demand such as database servers.