WiebeTech SS8 - Manual (Page 41)

W i e b e T e c h L L C
SAF-TE SCSI Accessed Fault-Tolerant Enclosures
SAF-TE commands are used to monitor information about the
status of the drives in the array, such as rebuilding, failed,
and spare. SAF-TE also monitors certain environmental
information about the system such as temperature, voltage,
power supply, and fan health.
SCSI Small Computer System Interface
SMART Self-Monitoring, Analysis and Reporting Technology
Monitoring tool to display drive’s health status.
Spare Spare Disk
A disk that is assigned that be a spare is used automatically
to replace a failed drive in a RAID array or a Volume Group.
Spare disks remain idle until the systems detects a failed
drive.
Types of Spares:
Dedicated Spare disks
These are spare disks that only belong to only one specified
VG for recovery/rebuilding.
Global Spare disks
The Global Spare disks are accessible by all VGs to do
rebuilding/recovery.
UDV
User Data Volume
Each VG could be divided into different UDVs. The UDVs
from one VG share the same RAID level, but may have
different volume capacity.
VG Volume Group
A Volume Group is a RAID array that consists of multiple
physical disks.
Write-Back cache write policy
A caching method that delays copying data modification to
system memory until absolutely necessary. This method
offers a better performance than write-through method, but at
the risk of losing the modifications if the system crashes.
Write-Through cache write policy
A caching method that writes data modifications to both the
cache memory and system memory. This method provides
data consistency between the cache and system memory, but
at a slower performance than the write-back method.
WWN World Wide Name (WWN)
Also known as World Wide Identifier (WWID). WWN is an
unique identifier created for each physical disk in a Fibre
Channel storage network.
ProSATA SS8 User Manual
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