Managing Storage; Raid Versus Storage Pools; Raid Types - Seagate Business Storage Windows Server 4-Bay NAS Administration Manual

3. Managing Storage

3. Managing Storage
Your Seagate server has predefined volumes. One volume is used for the Windows system
software, and another is for data. You cannot modify the system volume, but you can
reconfigure the data volume.

RAID Versus Storage Pools

With WSS 2012, you can group physical hard drives into storage pools or RAID
configurations. Grouping drives together creates a larger logical unit, increases reliability, and
enhances performance.
Storage pools are more flexible and can potentially include hundreds of disks. Storage pools
allow you to use the physical disk space more efficiently. Mirrored storage pools can be
resistant to disk failure.
RAID allows for storage to be shared between disks in ways that can improve reliability.
However, RAID configurations are less flexible than storage pools and are not easily
expanded.
Storage pools offer greater flexibility and ease of maintenance. Therefore, Seagate
recommends storage pools over RAID.
Note: Disks that are configured for RAID cannot be used in storage pools.

RAID Types

RAID levels vary according to the number of hard drives, protection, and performance.
RAID 0 - Striped volume: Unallocated space on two or more drives combined into a single
array. RAID 0 offers a small improvement in performance, but no data protection should a
hard drive fail.
RAID 1 - Mirrored volume: Unallocated space on two drives is combined into a single array.
The same data is simultaneously written to both drives. This provides a measure of data
safety if a single drive fails. However, you lose 50% of the total disk capacity due mirroring
the data.
RAID 5 - Striped volumes with distributed parity: Unallocated space on at least three hard
drives is combined into a single array. RAID 5 offers improved performance and data
protection. If a single drive fails, the data can be recovered. A RAID-5 volume requires space
on at least three separate physical disks. There is one-third-space overhead for RAID-5
disks. For example, if you create a RAID-5 volume from three 1TB drives, the resulting RAID-
5 volume will be 2TB.
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Seagate Business Storage Windows Server 4-Bay NAS Administration Guide 7