Chapter 4 Managing Your Storage; Volume Types - Buffalo TeraStation Pro WSS User Manual

Chapter 4 Managing Your Storage

Volume Types

The features of each volume type are explained below.
Notes:
• When a volume type is changed, all data stored in that volume is erased. Before executing these operations, back up
any important data.
• In this manual, "recovery" means reverting the TeraStation (including the data) to state prior to the drive failure. It
doesn't refer to reading data from a failed hard drive.
RAID 5 Volume
The unallocated areas of three or more hard drives are used as a single array.
If one drive in a RAID 5 array fails, data on the array can be recovered after the failed drive is replaced. However, if two or
more drives fail, all data is lost.
Mirrored Volume (RAID 1)
The unallocated areas of two drives are combined into a single RAID 1 array. Because the same data is written to both
drives simultaneously, if one drive fails, data can be recovered from the other drive. If both drives in the array fail, data
cannot be recovered.
Striped Volume (RAID 0)
In a striped volume, the unallocated areas of two or more drives are combined into a single logical volume using RAID 0.
However, data cannot be recovered if even a single drive fails.
Spanned Volume
In a spanned volume, the unallocated areas in multiple hard drives are joined to create a single logical volume. This
allows odd sizes of space on various drives to be combined efficiently. However, data cannot be recovered if even a
single hard drive failure occurs.
Simple Volume (JBOD)
The internal hard drives of the TeraStation are each used as individual drives. If a hard drive fails, the data on the failed
hard drive cannot be recovered.
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