Chapter 4 Managing Storage; Raid Arrays - Buffalo TeraStation TS3400D User Manual

Chapter 4 Managing Storage

RAID Arrays

TeraStations support many types of RAID. The type of RAID arrays available for use depends on how many drives are
installed in your TeraStation.
TeraStation
TS3400D
TS3400R
TS3200D
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 array.
• Hard drive capacity is shown in Settings in actual gigabytes. The Properties window in Windows may show
GiB instead, which will be a smaller number.
• After the RAID mode is changed (except when creating a RAID 0 array or JBOD), the TeraStation 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 on the LCD panel, do not turn off the TeraStation. If you do, the RAID check starts over.
• If the TeraStation is restarted or shut down while changing the RAID mode, the message displayed on the
LCD panel will change from I46 or I47 to I18.
RAID 6
*
RAID 6 arrays are available for TeraStations with 4 or more hard drives. RAID 6 combines 4 or more drives into a
single array. The usable space is equal to the sum of the capacity of all drives minus the capacity of two drives. For
example, if 4 drives are combined into a RAID 6 array, the usable space is the sum of the capacity of 2 drives. If 2
drives in the array are damaged, you can recover data by replacing them. If 3 or more drives are damaged, your data
is lost.
RAID 5
*
RAID 5 arrays are available for TeraStations 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 TeraStations 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.
Default RAID Mode
RAID 5
RAID 1
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