3Ware 9550SXU-16ML User Guide - Page 19
Table 2: Possible Configurations Based on # of Drives, Table 3: Drive Capacity
UPC - 693494971606
View all 3Ware 9550SXU-16ML manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 19 highlights
Understanding RAID Concepts and Levels Table 2: Possible Configurations Based on # of Drives # Drives Possible RAID Configurations 1 2 3 4 5 6 or more Single drive or hot spare RAID 0 or RAID 1 RAID 0 RAID 1 with hot spare RAID 5 RAID 5 + hot spare RAID 10 Combination of RAID 0, RAID 1, single disk RAID 5 + hot spare RAID 10 + hot spare Combination of RAID 0, RAID 1, hot spare, for single disk RAID 50 Depending on the number of drives, a RAID 50 may contain from 2 to 4 subunits. For example, with 12 drives, possible RAID 50 configurations include 2 subunits of 6, 3 subunits of 4, or 4 subunits of 3. With 10 drives, a RAID 50 will contain 2 subunits of 5 drives each. With 16 drives, a RAID 50 will contain 2 subunits of 8 drives or 4 subunits of 4 drives. Combination of RAID 0, 1, 5, 10, hot spare, and single disk Drive Capacity Considerations The capacity of each drive is limited to the capacity of the smallest drive in the array. The total array capacity is defined as follows: Table 3: Drive Capacity RAID Level Capacity RAID 0 RAID 1 RAID 5 (number of drives) X (capacity of the smallest drive) capacity of the smallest drive (number of drives - 1) X (capacity of the smallest drive) RAID 10 RAID 50 Storage efficiency increases with the number of disks: storage efficiency = (number of drives -1)/(number of drives) (number of drives / 2) X (capacity of smallest drive) (number of drives - number of groups of drives) X (capacity of the smallest drive) Through drive coercion, the capacity used for each drive is rounded down so that drives from differing manufacturers are more likely to be able to be used www.3ware.com 9