LaCie 5big Network 2 - Page 55

LaCie 5big Network 2 • DESIGN BY NEIL POULTON Administering Your LaCie 5big Network 2
User Manual page 55
RAID10: RAID 10 (also called RAID 1+0) is another RAID level that
combines the attributes of other levels, specifically RAID 1 and RAID
0. It is a “stripe of mirrored sets”, meaning that data is striped across
two mirrored arrays (Fig. 81). The Striping occurs between arrays
and the mirroring occurs within the same array, which makes the
rebuilding very fast. This RAID mode is therefore only available if the
5big Network 2 has four disks installed.
RAID0: RAID 0 (also called Spanning mode in some LaCie devices),
is the fastest RAID mode. In a RAID 0 array, the available capacities
of each disk are added together so that one logical volume mounts
on the computer (Fig. 82). It offers the best performance but no
protection in the case that a disk fails.
CAUTION: In a RAID0 array, if one physical disk in the array fails,
the data of all disks becomes inaccessible because parts of the data
have been written to all disks.
RAID1: RAID 1 is a secure RAID mode that is available if the 5big
Network 2 has only two disks installed. RAID 1 provides data safety
since all data is written to each disk at the same time (Fig. 83). In the
event of a single disk failure, data remains available on the other
disk. Due to the time it takes to write the data twice, performance
is slightly reduced. RAID 1 is a good choice when safety is more
important than speed. However RAID 1 also reduces the available
disk space by 50% due to the need to write each bit of data on each
hard drive.
Fig. 81
RAID 1 RAID 1
RAID 0
A2
A4
A6
A8
RAID 10
A2
A6
A8
A4
A1
A3
A7
A5
A1
A3
A5
A7
Disk 1 Disk 2 Disk 3 Disk 4
RAID 1
A1
B1
C1
D1
E1
A1
B1
C1
D1
E1
Disk 1 Disk 2
Fig. 82
Fig. 83
K:B=)
Disk 1 Disk 2 Disk 3 Disk 4 Disk 5
A1
B1
C1
D1
A2
B2
C2
D2
A3
B3
C3
D3
A4
B4
C4
D4
A5
B5
C5
D5
E1 E2 E3 E4 E5