Dell Compellent Series 30 User Manual
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NFS
Network File System
NIC
Network Interface Card
P
Pagepool
A pool of storage from which volumes are stored. See
.
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.