How Dynamicraid Works - Overland Storage SnapServer Administrator's Manual

SnapServer 7.0 Administrator's Guide
DynamicRAID versus Traditional RAID
The following table compares the features of these two RAID types:
Feature
RAID Levels
RAID Creation
RAID Expansion
Mixed Drive
Capacities
Mixed Drive Types All drives in a given Storage Pool must
Dynamic Volumes
Snapshots
Volume Size
Filesystem
Spanning
Quotas/Size Limits Volume size limits can be either

How DynamicRAID Works

Step 1: DynamicRAID detects all available disk drives on the SnapServer.
Step 2: Select the parity setting:
• One disk drive – No parity protection only.
• Two or Three disk drives – Single parity protection only.
• Four or more disk drives – Choose either Single or Dual parity protection.
Step 3: The software configures the SnapServer.
Step 4: Use the following options to fine-tune the configuration:
• Storage > Storage Pools
• Storage > Volumes
• Security > Shares
10400317-001 10/2011
DynamicRAID
Single or dual parity options that can be
changed dynamically.
Automatic after selection of parity and
snapshot space reservation.
Can be expanded by adding new
member drives.
Additional capacity on larger drives can
be utilized within the constraints of
single- or dual parity protection.
Additional capacity on larger drives can
be utilized if there are enough larger
drives to satisfy the parity configuration
of DynamicRAID.
be the same type of drive (for example,
SAS 15K).
Volumes grow and shrink on demand.
Snapshots are by Storage Pool and can
be mounted for individual file recovery.
Limited by the Storage Pool.
Filesystem is limited to a given volume
on a given Storage Pool.
specified or unlimited.
("Storage Pools" on page
("Volumes" on page
("Shares" on page 7-6)
©2010-11 Overland Storage, Inc.
A – DynamicRAID Overview
Traditional RAID
Manually created RAID sets 0, 1, 5, 6, or
10. Must delete and recreate to change.
Manual selection of drives, RAID set
level, and snapshot space.
Can be grouped with other RAIDs to
increase the space available to volumes.
Only the capacity equivalent to the
smallest drive is used on each drive in
the RAID set.
Different types of drives can be mixed in
a head unit or expansion unit (using
different RAID sets and volumes).
Volumes grow on demand.
Snapshots are by volume and can be
mounted for either individual file
recovery or volume rollback.
Limited by the storage in the head unit
plus all the expansion units.
Filesystem can span multiple volumes
concatenated together using Instant
Capacity Expansion (ICE)
User and Group size quotas are
supported by volume.
4-2)
4-8)
A-2