Whitepaper: X-RAID2 vs Flex-RAID

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Flex-rAId

Flex-RAID architecture has two major advantages:

•SupportmultiplevolumesperReadyNAS.

•RAIDlevelcanbeselectedformaximumcapacity,redundancy,orperformance.

The NETGEAR Flex-RAID technology allows you to choose from among several industry-standard RAID levels:

 • JBod. This most basic RAID level does not protect your data from loss if one of your drives fails. JBOD is available

only on volumes consisting of a single hard disk.

 •rAId 0. RAID 0 distributes data across multiple disks, resulting in improved disk performance compared to systems

that do not use RAID formatting. The total capacity of your storage system equals the capacity of all of your disk

drives. RAID 0 is available on volumes consisting of two or more hard disks.

 • rAId 1. This RAID level provides full redundancy of your data, because it duplicates data across multiple disks.

Exactly the same data is stored on two or more disks at all times. RAID 1 protects your data from loss if one disk

fails. The total capacity of your storage system equals the capacity of your smallest disk.

 • rAId 5. This RAID level also provides data redundancy, but it requires at least three disks. RAID 5 uses the capacity

of one disk to protect you from data loss if one disk fails. Your data is distributed across multiple disks to improve disk

performance. The total capacity of your storage system equals the capacity of all your disks minus the capacity of

one disk. It is supported on systems with at least four drive bays.

 •rAId 6. This RAID level can recover from the loss of two disks. Your data is distributed across multiple disks to

improve disk performance. The total capacity of your storage system equals the capacity of all your disks minus

the capacity of two disks. It is supported on systems with at least four drive bays.

 • rAId 10 (or 1+0). This RAID level uses both RAID 1 and RAID 0 technology. First, your data is duplicated so that

exactly the same data is stored on two or more disks. Then, the data is distributed across additional disks to improve

disk performance. It is supported on systems with at least four drive bays.

The Flex-RAID levels that you can select depend on the number of disks included in the volume. The following table describes

the Flex-RAID levels that are available for a given number of disks. It also indicates whether adding a disk for data protection

is possible for each conﬁguration.

Number of

Disks per

Volume

RAID Level Can I add a disk for data protection?

1 RAID 1 Yes. (Additional disk provides redundancy.)

1 JBOD No. (JBOD is available only for volumes consisting of one disk)

2 RAID 1 No. (Volume protection is already redundant.)

2 or more RAID 0 No. (RAID 0 does not oer protection.)

3 or more RAID 5 Yes. (Additional disk provides dual redundancy and converts the volume to

RAID 6.)

4 or more

(even number)

RAID 10 No. (Volume protection is already redundant.)

4 or more RAID 6 No. (Volume is already protected with dual redundancy.)

Table 1. Flex-RAID levels and data protection

NETGEAR, the NETGEAR logo, X-RAID2 and ReadyNAS are trademarks and/or registered trademarks of NETGEAR, Inc. and/or its subsidiaries in the United

States and/or other countries. Other brand names mentioned herein are for identiﬁcation purposes only and may be trademarks of their respective hold-