Nvidia 4 - Manual (Page 10)

6 MediaShield User’s Guide – Version 4.0
C HAPTER 1
About NVIDIA® MediaShield™
RAID 1
How RAID 1 Works
In a RAID 1 array, every read and write is carried out in parallel across two disk drives.
The mirrored—or backup—copy of the data can reside on the same disk or on a second
redundant drive in the array. RAID 1 provides a hot-standby copy of data if the active
volume or drive is corrupted or becomes unavailable due to a hardware failure. RAID 1
techniques can be applied for high-availability solutions, or as a form of automatic backup
that eliminates tedious manual backups to more expensive and less reliable media.
Figure 1.2 RAID 1 Array Diagram
RAID 1 provides complete data redundancy, but at the cost of doubling the required data
storage capacity, resulting in 50% capacity utilization. Performance is roughly the same as
for a single drive, although in some instances the dual write may be somewhat slower.
Summary of Features and Benefits
• Benefits: Provides 100% data redundancy. Should one drive fail, the controller
switches to the other drive.
• Drawbacks: Requires two drives for the storage space of one drive. Performance is
impaired during drive rebuilds.
• Uses: RAID 1 is ideal for small databases or any other application that requires fault
tolerance and minimal capacity.
• Drives: Minimum, 2. Maximum, 2.
• Fault Tolerance: Yes