Setup Guide

57
NFS
Network File System
NIC
Network Interface Card
P
Pagepool
A pool of storage from which volumes are stored. See Storage Type on page 60.
Physical Port
The physical connection point on servers, switches, Storage Center controller, and disk
drive enclosures that is used to connect to other devices in the system.
R
RAID (Redundant Array of Independent Disks)
A way of encoding data over multiple physical disks to ensure that if a hard disk fails a
redundant copy of the data can be accessed. Example protection schemes include
mirroring and parity protection.
RAID 0
Stripes data but provides no redundancy. If one disk fails, all data is lost. Do not use RAID
0 unless data is backed-up elsewhere.
RAID 5-5 and 5-9
Maintains a logical copy of the data using a mathematically derived rotating parity stripe
across 5 or 9 disks. The parity stripe is derived from the data stripes. This method has less
overhead for the redundant information than RAID 10; however write performance is slower
than RAID 10 due to the calculation of the parity stripe for every write. RAID 5 protects
against data loss when any single disk fails. RAID 5-5 is 80% efficient. RAID 5-9 is 89%
efficient.
RAID 6-6 and 6-10
RAID 6 protects against data loss when any 2 disks fail. RAID 6-6 is 67% efficient. RAID 6-
10 is 80% efficient. .
RAID 10
Striped and mirrored. Provides both data availability and top performance. Maintains a
minimum of one full copy of all data on the volume. RAID 10 provides optimum Read / Write
performance, increased probability of withstanding multiple failures, and the fastest
restoration of data.