HP StorageWorks 8000 NAS - Manual (Page 230)

228 Glossary
With NFS, computers connected to a network operate as clients while
accessing remote files, and as servers while providing remote users access to
local shared files. The NFS standards are publicly available and widely used.
P
Package control log Package control log Package control log Package control log A log file is maintained for each package in a cluster. The software and the
package monitor log messages that are specific to the package log files. (This
feature is available only on high-availability NAS devices.)
Packet Packet Packet Packet A block of information sent across a network. Packets contain header (which
handle addressing), error correction, checksums, and data.
Permission Permission Permission Permission The ability of a particular user in a multi-user computer environment to access
a particular resource by means of a user account. Permissions are stored in
the system, in a file called a permissions log. Permissions are checked when a
user attempts to access a resource.
Permission bits Permission bits Permission bits Permission bits Bits that identify the read/write/execute (rwx) privileges for a UNIX file's
owner, group, and anyone else that needs access to the file (other).
Physical drive Physical drive Physical drive Physical drive A term for the hard drives installed in the NAS server. The NAS server can
contain up to 12 physical drives.
Primary Domain Primary Domain Primary Domain Primary Domain
Controller (PDC) Controller (PDC) Controller (PDC) Controller (PDC)
A server that has been assigned to become the primary authentication server
for the Windows NT domain. It stores a copy of the Security Accounts
Manager (SAM) database and uses this database to authenticate users.
R
RAID (Redundant RAID (Redundant RAID (Redundant RAID (Redundant
Array of Array of Array of Array of
Independent Disks) Independent Disks) Independent Disks) Independent Disks)
RAID is a method of combining several disk drives into a single logical
storage unit. RAID offers the advantage of fault tolerance by providing real-
time data recovery when a disk drive fails, increasing system uptime and
network availability. RAID also increases system performance when multiple
drives work together.
Redundancy group Redundancy group Redundancy group Redundancy group Group of physical disks that contain redundant data, as defined by the RAID
level assigned to the data. A redundancy group is also divided into logical
units (LUNs), addressable by the host. See the HP Surestore Virtual Array
VA7100 and VA7400 User And Service Guide for more information on how
the VA7100 and VA7400 series differ in their implementation of redundancy
groups.