Easy To Use Features; Instant Availability/Background Initialization; Array Roaming; Online Capacity Expansion - Sans Digital Mobileraid MR8X Detailed User's Manual

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SAS-to-SATA II RAID Subsystem

1.5.3 Easy to Use Features

RAID 0 and RAID 1 Volume Set can be used immediately after the creation. But the RAID 3,

5 and 6 Volume Sets must be initialized to generate the parity. In the Background Mode

initialization, the initialization proceeds as a background task, the Volume Set is fully

accessible for system reads and writes. The operating system can instantly access to the

newly created Volume Sets without waiting for the initialization to be completed. One

disadvantage of this is that the initialization process takes longer time. In Foreground Mode

initialization, the initialization process is faster but must be completed first before the

Volume Set is ready for system access.

The RAID subsystem stores configuration information both in NVRAM and on the disk drives.

This protects the configuration settings in the case of a disk drive or controller failure. Array

roaming allows the administrator the ability to move a complete Raid Set to another system

without losing RAID configuration and data on that Raid Set. If a RAID enclosure fails to

work, the Raid Set disk drives can be moved to another enclosure and inserted in any order.

Online Capacity Expansion makes it possible to add one or more physical drives to a Raid

Set, while the server is in operation, eliminating the need to backup and restore after

reconfiguring the Raid Set. When disks are added to a Raid Set, unused capacity is added at

the end of the Raid Set. Data on the existing Volume Sets residing on that Raid Set is

redistributed evenly across all the disks. A contiguous block of unused capacity is made

available on the Raid Set. The unused capacity can be used to create additional Volume Set.

The expansion process is illustrated as follows.

Installation and Configuration Manual

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