Users Guide

• RAID 6 — Stripes data across the physical disks, and uses two sets of parity information for additional
data redundancy. If one or two physical disks fail, the data can be rebuilt using the parity information.
RAID 6 offers good data redundancy and read performance but slower write performance.
• RAID 10 — Combines mirrored physical disks with data striping. If a physical disk fails, data can be
rebuilt using the mirrored data. RAID 10 offers good read and write performance with good data
redundancy.
• RAID 50 — A dual-level array that uses multiple RAID 5 sets in a single array. A single physical disk
failure can occur in each of the RAID 5 without any loss of data on the entire array. Although the RAID
50 has increased write performance, its performance decreases, data or program access gets slower,
and transfer speeds on the array are affected when a physical disk fails and reconstruction takes place.
• RAID 60 — Combines the straight block level striping of RAID 0 with the distributed double parity of
RAID 6. The system must have at least eight physical disks to use RAID 60. Failures while a single
physical disk is rebuilding in one RAID 60 set do not lead to data loss. RAID 60 has improved fault
tolerance because more than two physical disks on either span must fail for data loss to occur.
NOTE: Depending on the type of controllers, some RAID levels are not supported.
Minimum disk requirement for different RAID levels
Table 8. RAID level and number of disks
RAID Level Minimum Number of Disks
0 1*
1 2
5 3
6 4
10 4
50 6
60 8
* For PERC S110 and S130 RAID controllers, a minimum of two hard-disk drives are required.
Selecting physical disks
Use the Select Physical Disks screen to select the physical disks to be used for the virtual drive and select
the physical disk drive-related properties.
The number of physical disks required for the virtual disk varies depending on the RAID level. The
minimum and maximum numbers of physical disks required for the RAID level are displayed on the
screen.
• Protocol — Select the protocol for the disk pool: Serial Attached SCSI (SAS) or Serial ATA (SATA). SAS
drives are used for high performance, while SATA drives provide a more cost-effective solution. A disk
pool is a logical grouping of physical disk drives on which one or more virtual drives can be created.
The protocol is the type of technology used to implement RAID.
• Media Type — Select the media type for the disk pool: Hard Disk Drives (HDD) or Solid State Disks
(SSD). HDDs use traditional rotational magnetic media for data storage and SSDs implement flash
memory for data storage.
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