Glyph ForteRAID - Manual (Page 3)

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About the ForteRAID and Drive Modes
The ForteRAID enclosure contains four hard disk drives, which function as one single volume. Through the
use of the Glyph Manager software utility, it supports six drive modes: RAID 0, 1, 3, 5, 10, and Spanning. Each
drive mode has its own advantages, depending upon the application.
RAID 0 (striping) is designed for increased speed but offers no redundancy benefits. RAID 0 spreads
data across array members in blocks, and is ideal for situations where speed and capacity are most
important. It’s a proven technology for video editing, working with huge graphics files, sound librar-
ies, and streaming instruments that play hundreds of samples simultaneously. RAID 0 provides the
full capacity of the drives, and is the default shipping drive mode. Since data is written without any
form of parity data-checking, it allows for the fastest data transfer of all other RAID levels. However,
if one drive becomes damaged, the data on both drives can become corrupted. RAID 0 is not redun-
dant or fault tolerant like RAID levels 1, 3, and 5, but the trade off is that it’s the fastest of all RAID
levels. MAKE SURE TO BACKUP YOUR DATA OFTEN!
RAID 1 (mirroring) uses only two of the 4 internal drives. It offers the data redundancy and real-time
backup by writing the same data to two hard drives at the same time. Should a drive failure happen,
data is still available on the remaining drive. Usable capacity is equal to capacity of 1 drive. For ex-
ample, a 4TB ForteRAID will be seen as a 1TB drive. Reading and writing occurs on both drives simul-
taneously so that each of the drives contains exactly the same data, mirroring each other. If either of
the drives should fail the other is there to seamlessly continue to provide operation.
RAID 3 (striping with a dedicated parity drive) offers speed and data redundancy by using parity
data which is stored on a dedicated drive. Should a drive failure happen, the remaining members of
the array calculate the missing data and rebuild to a spare drive. The spare drive can be inserted after
the failure, or can be online and waiting (hot spare). For RAID 3, usable capacity is 3/4 of the entire
capacity. For RAID 3 + hot spare, usable capacity is half the entire capacity.
RAID 5 (striping with distributed parity) offers speed and data redundancy by using parity data
which is striped across all drives. Should a drive failure happen, the remaining members of the array
calculate the missing data and rebuild to a spare drive. The spare drive can be inserted after the fail-
ure, or can be online and waiting (hot spare). For RAID 5, usable capacity is 3/4 of the entire capacity.
For RAID 5 + hot spare, usable capacity is half the entire capacity.
RAID 10 (striping + mirroring) creates two pairs of mirrored drives, and stripes across them for a
very good balance of speed and redundancy. Usable capacity is equal to half of the entire capacity.
RAID 10 is perfect for situations where the data integrity is more important than the capacity, such as
audio recording and editing, photography, and sample libraries/sound libraries.
Spanning mode simply shows all four drives as one large volume and data is written sequentially
across them. When the first drive fills to the limit, data is then written to the next drive. This mode
is useful for applications requiring large volumes, but not requiring the speed of RAID 0. Spanning
provides the full capacity of the drives, with no benefits to speed or redundancy.