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Introduction
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1.4.3.4 Online RAID Level and Stripe Size Migration
A user can migrate both the RAID level and stripe size of an existing Volume
Set, while the server is online and the Volume Set is in use. Online RAID
level/stripe size migration can prove helpful during performance tuning activi-
ties as well as in the event that additional physical disks are added to the
SurfRAID TRITON Mini. For example, in a system using two drives in RAID
level 1, you could add capacity and retain fault tolerance by adding one drive.
With the addition of third disk, you have the option of adding this disk to your
existing RAID logical drive and migrating from RAID level 1 to 5. The result
would be parity fault tolerance and double the available capacity without tak-
ing the system off.
1.4.4 High availability
1.4.4.1 Creating Hot Spares
A hot spare drive is an unused online available drive, which is ready for re-
placing the failure disk drive. In a RAID level 1, 0+1, 3, or 5 RAID Set, any
unused online available drive installed but not belonging to a RAID Set can be
defined as a hot spare drive. Hot spares permit you to replace failed drives
without powering down the system. When SurfRAID TRITON Mini detects a
drive failure, the system will automatically and transparently rebuild the RAID
set using hot spare drives. The RAID Set will be reconfigured and rebuilt in
the background, while the SurfRAID TRITON Mini continues to handle system
requests. During the automatic rebuild process, system activity will continue
as normal, however, system performance and fault tolerance will be affected.
Important:
The hot spare must have at least the same or more capacity as the
drive it replaces.