SilverStone DS351 [10/119] Sii 4726 storage policies

SiI 4726 storage policies

The following terms represent SiI 4726 configuration options, or storage policies, for mapping physical to

virtual drives. The end-user can choose from these policies when s/he configures the volumes (virtual

drives) using the Basic Configuration Wizard or the Advanced Configuration Wizard.

JBOD A storage policy that grants the host computer direct access to a physical disk drive. With

JBOD (just a bunch of disks), the number of available virtual drives is equal to the number

of physical drives. JBOD is also called the bypass mode because the host bypasses the

SteelVine virtualization engine to access the drive directly.

SAFE A storage policy in which all data are stored in duplicate on separate hard disk drives to

protect against data loss due to drive failure. At least two hard disk drives mirror each

other at all times, equivalent to RAID 1. Every write operation goes to both drives. SAFE

provides

the highest level of data protection, but halves the amount of storage space because all

data must be stored twice.

To implement the SAFE storage policy, the Basic Configuration Wizard creates two

volumes. Each volume consists of two hard disk drives that mirror each other. The

remaining hard disk drive is specified as a Hot Spare for both volumes.

BIG A storage policy configuration in which multiple physical hard disk drives are

concatenated and treated as one large volume. This configuration allows the end-user to

increase logical volume size beyond the capacity of individual hard disk drives. BIG

provides the maximum amount of storage space, but no additional performance or data

redundancy.

The Basic Configuration Wizard implements the BIG storage policy by concatenating all

the hard disk drives into a single volume.

FAST A storage policy in which I/O processing is balanced evenly in a method known as striping,

equivalent to RAID 0. Striping increases storage operation speed as each portion of data

is divided into segments that are written to different disks simultaneously. FAST offers the

best performance in terms of speed, but has no redundancy of data.

To implement the FAST storage policy, the Basic Configuration Wizard creates a

single volume of up to five hard disk drives in a striped format.

SAFE and BIG A storage policy in which one-half of the available storage space is concatenated. The

other half mirrors the first half to provide full data redundancy.

To implement the SAFE and BIG storage policy, the Basic Configuration Wizard creates a

volume consisting of four hard disk drives and designates the remaining drive as a Hot

Spare.

SAFE and FAST A storage policy in which an array of stripes is created. Each stripe consists of two

mirrored drives. SAFE and FAST provides the I/O load balancing features of striping

and the added reliability of mirrored data, equivalent to RAID 1+0. Data are written to

mirrored disks in a striped format.

To implement the SAFE and FAST storage policy, the Basic Configuration Wizard creates

a virtual drive consisting of four hard disk drives and designates the remaining drive as a

Hot Spare.