Buffalo LS441D1604-EU [34/105] Raid arrays

Chapter 4 Managing Storage

RAID Arrays

The default RAID mode is RAID 5.

Notes:

• If you change the RAID mode, all data on the array is deleted. This is true for every procedure in this chapter.

Always back up any important data before performing actions that affect your RAID.

• After the RAID mode is changed (except when creating a RAID 0 array or JBOD), the LinkStation performs

a RAID check that will take about 10 hours per TB. File transfers are slower during this period. While the I17

message is displayed in NAS Navigator2, do not turn off the LinkStation. If you do, the RAID check will start

over.

RAID 5

RAID 5 arrays are available for LinkStations with 3 or more hard drives. RAID 5 combines 3 or more drives into a

single array. The usable space is equal to the sum of the capacity of the hard drives minus the capacity of one drive.

For example, if 4 drives are combined into a RAID 5 array, the usable space is the sum of 3 drives. If one drive in the

array is damaged, you can recover data by replacing the damaged drive. If two or more drives are damaged at the

same time, your data is lost.

RAID 10

RAID 10 arrays are available for LinkStations with 4 or more hard drives. In this mode, mirrored pairs of drives in RAID

1 arrays are combined into a RAID 0 array. The usable space is equal to the capacity of the smallest drive multiplied

by the number of hard drives divided by 2.

RAID 1

Combines 2 drives into a mirrored array. The available space in the array is the capacity of a single drive. Identical

data is written to each drive. If a drive is damaged, data can be recovered by replacing the damaged drive. As long

as one drive in the array remains undamaged, all data in the array can be recovered.

RAID 0

Combines 2 or more hard drives into a single array. The usable disk space is the total space of all drives used. This

simple RAID mode offers faster performance than RAID modes that include parity. If a single drive in the array fails,

then all data in the array is lost.

JBOD

This mode uses the hard drives inside the LinkStation as individual drives. The disk space you can use is the total

capacity of all drives in the LinkStation. If any drive is damaged, then the data on that drive is lost.