3Ware 8006-2LP User Guide - Page 17

RAID 1 arrays offer fault tolerance - performance

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Unlike other RAID levels, RAID 0 is not redundant, so loss of any disk drive results in loss of all user data. Figure 1. RAID 0 Configuration Example RAID 1 arrays offer fault tolerance Mirrored disk arrays write data to two drives using RAID 1 algorithms (see Figure 2). This gives your system fault tolerance by preserving the data on one drive if the other drive fails. Fault tolerance is a basic requirement for mission critical systems like web and database servers. Figure 2. RAID 1 Configuration Example TwinStorTM Technology adds performance to 3ware's mirrored disk arrays Traditional mirroring techniques do little to improve performance. The adaptive algorithms found in 3ware's TwinStor technology boost performance by distinguishing between random and sequential read requests. For the sequential requests generated when accessing large files, both drives are used, with the heads simultaneously reading alternating sections of the file. For the smaller random transactions, the data is read from a single optimal drive head. RAID 10 arrays maximize performance and fault tolerance When drives are configured as a striped mirrored array, the disks are configured using both RAID 0 and RAID 1 techniques, thus the name RAID 10 (see Figure 3). A minimum of four drives are required to use this technique. The first two drives are mirrored as a fault tolerant array using RAID 1. The third and fourth drives are mirrored as a second fault tolerant www.3ware.com 9

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9
Unlike other RAID levels, RAID 0 is not redundant, so loss of any disk drive
results in loss of all user data.
Figure 1.
RAID 0 Configuration Example
RAID 1 arrays offer fault tolerance
Mirrored disk arrays write data to two drives using RAID 1 algorithms (see
Figure 2). This gives your system fault tolerance by preserving the data on
one drive if the other drive fails. Fault tolerance is a basic requirement for
mission critical systems like web and database servers.
Figure 2.
RAID 1 Configuration Example
TwinStor
TM
Technology adds performance to 3ware’s
mirrored disk arrays
Traditional mirroring techniques do little to improve performance. The
adaptive algorithms found in 3ware’s TwinStor technology boost performance
by distinguishing between random and sequential read requests. For the
sequential requests generated when accessing large files, both drives are used,
with the heads simultaneously reading alternating sections of the file. For the
smaller random transactions, the data is read from a single optimal drive head.
RAID 10 arrays maximize performance and fault
tolerance
When drives are configured as a striped mirrored array, the disks are
configured using both RAID 0 and RAID 1 techniques, thus the name RAID
10 (see Figure 3). A minimum of four drives are required to use this
technique. The first two drives are mirrored as a fault tolerant array using
RAID 1. The third and fourth drives are mirrored as a second fault tolerant