Proware EP-4643S2D2-F8S6, User Manual, Page: 22 / 151

Fibre to SAS/SATA Disk Array
22 User Manual
1.5 High Availability
1.5.1 Creating Hot Spares
A hot spare drive is an unused online available drive, which is ready to replace a failed
disk drive. In a RAID level 1, 10, 3, 5, 6, 30, 50, or 60 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 the Disk Array detects a drive failure, the system will do automatic and
transparent rebuild using the hot spare drives. The Raid Set will be reconfigured and
rebuilt in the background while the Disk Array continues to handle system request.
During the automatic rebuild process, system activity will continue as normal, however,
the 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.
1.5.2 Hot-Swap Disk Drive Support
The Disk Array has built-in protection circuit to support the replacement of SATA II
hard disk drives without having to shut down or reboot the system. The removable
hard drive tray can deliver “hot swappable” fault-tolerant RAID solution at a price
much less than the cost of conventional SCSI hard disk Disk Arrays. This feature is
provided in the Disk Array for advance fault tolerant RAID protection and “online” drive
replacement.
1.5.3 Hot-Swap Disk Rebuild
The Hot-Swap feature can be used to rebuild Raid Sets with data redundancy such as
RAID level 1, 10, 3, 5, 6, 30, 50 and 60. If a hot spare is not available, the failed disk
drive must be replaced with a new disk drive so that the data on the failed drive can
be rebuilt. If a hot spare is available, the rebuild starts automatically when a drive
fails. The Disk Array automatically and transparently rebuilds failed drives in the
background with user-definable rebuild rates. The Disk Array will automatically
continue the rebuild process if the subsystem is shut down or powered off abnormally
during a reconstruction process.