Hitachi Storage Navigator Modular 2 User Guide

							Understanding IP addressesD–9
Hitachi Storage Navigator Modular 2 User’s Guide
• IPv6 multicasting is used on the local link to search for the array’s IPv6 
address. Prior to having Navigator 2 search for the array, configure the 
array and the computer in which Navigator 2 is installed to reside on 
the same link.
• If the computer where Navigator 2 is installed has two or more NICs 
connected to separate network segments, Navigator 2 can only access 
the LAN whose addresses were specified when Navigator 2 was 
installed.
Example 2
Figure D-5 shows a configuration where a computer with Navigator 2 and 
another computer are configured with different IPv6 addresses.
Figure D-5:  Sample Configuration 2
In this configuration:
• The array uses 2000/tcp and 28355/tcp to communicate with Navigator 
2. If the computer is connected directly to the array, but cannot 
communicate through the router, the router may have blocked ports. In 
this case, configure the router to permit 2-way communication to ports.
• The computer in which Navigator 2 is installed (Computer A) uses 
23015/tcp and 1099/tcp to communicate with Computer B. If Computer 
A can be connected directly to the array, but cannot communicate 
through the router, the router may have blocked ports. In this case, 
configure the router to permit 2-way communication to ports.
• IPv6 multicasting is used on the local link to search for the array’s IPv6 
address. Prior to having Navigator 2 search for the array, configure the 
array and the computer in which Navigator 2 is installed to reside on 
the same link.
• If the computer where Navigator 2 is installed has two or more NICs 
connected to separate network segments, Navigator 2 can only access 
the LAN whose addresses were specified when Navigator 2 was 
installed. 
						

							D–10Understanding IP addresses
Hitachi Storage Navigator Modular 2 User’s Guide 
						

							Glossary–1
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Glossary
This glossary provides definitions of general storage networking 
terms as well as specific terms related to the technology that 
supports Hitachi Data Systems products. Click the letter of the 
glossary section to display that page. 
						

							Glossary–2
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•
1000BASE-T
A specification for Gigabit Ethernet over copper wire. The standard 
defines 1 Gbps data transfer over distances of up to 100 meters using 
four pairs of Category 5 balanced copper cabling and a 5-level coding 
scheme.
Array
A set of hard disks grouped logically together to function as one 
contiguous storage space. 
ATA
Advanced Technology Attachment, a disk drive implementation that 
integrates the controller on the disk drive.
BIOS
Basic Input Output System, built-in software code that determines the 
functions that a computing device can perform without accessing 
programs from a disk.
Bps
Bits per second, the standard measure of data transmission speeds.
BSD syslog protocol
This protocol has been used for the transmission of event notification 
messages across networks for many years. While this protocol was 
originally developed on the University of California Berkeley Software 
Distribution (BSD) TCP/IP system implementations, its value to 
operations and management has led it to be ported to many other 
operating systems as well as being embedded into many other 
networked devices.
Cache
A temporary, high-speed storage mechanism. It is a reserved section of 
main memory or an independent high-speed storage device. Two types 
of caching are found in computers: memory caching and disk caching. 
Memory caches are built into the architecture of microprocessors and 
often computers have external cache memory. Disk caching works like 
memory caching; however, it uses slower, conventional main memory 
that on some devices is called a memory buffer.
Capacity
The amount of information (usually expressed in megabytes) that can 
be stored on a disk drive. It is the measure of the potential contents of 
a device; the volume it can contain or hold. In communications,  
						

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capacity refers to the maximum possible data transfer rate of a 
communications channel under ideal conditions.
Challenge Handshake Authentication Protocol
A security protocol that requires users to enter a secret for access.
CHAP
See Challenge Handshake Authentication Protocol.
command control interface (CCI)
Hitachis Command Control Interface software provides command line 
control of Hitachi array and software operations through the use of 
commands issued from a system host. Hitachi’s CCI also provides a 
scripting function for defining multiple operations.
command line interface (CLI)
A method of interacting with an operating system or software using a 
command line interpreter. With Hitachi’s Storage Navigator Modular 
Command Line Interface, CLI is used to interact with and manage 
Hitachi storage and replication systems.
DHCP
Dynamic Host Configuration Protocol, allows a computer to join an IP-
based network without having a pre-configured IP address. DHCP is a 
protocol that assigns unique IP addresses to devices, then releases and 
renews these addresses as devices leave and re-join the network.
Differential Management Logical Unit (DMLU)
The volumes used to manage differential data in a storage system. In a 
TrueCopy Extended Distance system, there may be up to two DM 
logical units configured per storage system. For Copy-on-Write and 
ShadowImage, the DMLU is an exclusive volume used for storing data 
when the array system is powered down.
Duplex
The transmission of data in either one or two directions. Duplex modes 
are full-duplex and half-duplex. Full-duplex is the simultaneous 
transmission of data in two direction. For example, a telephone is a full-
duplex device, because both parties can talk at once. In contrast, a 
walkie-talkie is a half-duplex device because only one party can 
transmit at a time. 
						

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Fabric
The hardware that connects workstations and servers to storage 
devices in a SAN. The SAN fabric enables any-server-to-any-storage 
device connectivity through the use of fibre channel switching 
technology.
FC
Fibre channel.
Firmware
Software embedded into a storage device. It may also be referred to as 
Microcode.
Full-duplex
The concurrent transmission and the reception of data on a single link.
Gbps
Gigabit per second.
GUI
Graphical user interface.
HBA
Host bus adapter, a circuit board and/or integrated circuit adapter 
installed in a workstation or server that provides input/output 
processing and physical connectivity between a server and a storage 
device. An iSCSI HBA implements the iSCSI and TCP/IP protocols in a 
combination of a software storage driver and hardware.
HDD
Hard disk drive.
Initiator
A system component that originates an I/O command over an I/O bus 
or network, such as an I/O adapters or network interface cards.
I/O
Input/output. 
						

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IP
Internet Protocol, specifies the format of packets and addressing 
scheme. Most networks combine IP with a higher-level protocol called 
Transmission Control Protocol (TCP), which establishes a virtual 
connection between a destination and a source.
IP address
An identifier for a computer or device on a TCP/IP network. Networks 
using the TCP/IP protocol route messages based on the IP address of 
the destination. The format of an IP address is a 32-bit numeric 
address written as four numbers separated by periods. Each number 
can be zero to 255 (for example, 192.168.0.200).
IP-SAN
Block-level Storage Area Networks over TCP/IP using the iSCSI 
protocol.
iSCSI
Internet SCSI, an IP-based standard for connecting data storage 
devices over a network and transferring data using SCSI commands 
over IP networks. iSCSI enables a Storage Area Network to be 
deployed in a Local Area Network.
iSNS
Internet Storage Name Service, a protocol that allows automated 
discovery, management and configuration of iSCSI devices on a TCP/IP 
network.
L
LAN
Local Area Network, a computer network that spans a relatively small 
area, such as a single building or group of buildings. 
LU
Logical unit.
LUN
Logical unit number. 
						

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Middleware
Software that connects two otherwise separate applications. For 
example, a middleware product can be used to link a database system 
to a Web server. Using forms, users request data from the database; 
then, based on the users requests and profile, the Web server returns 
dynamic Web pages to the user.
MIB
Message Information Block.
NIC
Network Interface Card, an expansion board in a computer that allows 
the computer to connect to a network.
NTP 
Network Time Protocol, a protocol for synchronizing the clocks of 
computer systems over packet-switched, variable-latency data 
networks. NTP uses UDP port 123 as its transport layer. It is designed 
particularly to resist the effects of variable latency (jitter).
Pool volume
A pool volume is used to store backup versions of files, archive copies 
of files, and files migrated from other storage.
primary volume  (P-VOL)
The storage volume in a volume pair. It is used as the source of a copy 
operation. In copy operations a copy source volume is called the P-VOL 
while the copy destination volume is called S-VOL (secondary volume).
RAID
Redundant Array of Independent Disks, a disk array in which part of the 
physical storage capacity is used to store redundant information about 
user data stored on the remainder of the storage capacity. The 
redundant information enables regeneration of user data in the event 
that one of the arrays member disks or the access path to it fails. 
SNIA. 
						

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RAID 6
An extension of the RAID 5 array, that allows for two simultaneous 
drive failures without downtime or data loss.recovery point objective 
(RPO).
After a recovery operation, the recovery point objective (RPO) is the 
maximum desired time period, prior to a disaster, in which changes to 
data may be lost. This measure determines up to what point in time 
data should be recovered. Data changes preceding the disaster are 
preserved by recovery.
SAN
Storage Area Network, a network of shared storage devices that 
contain disks for storing data.
SAS
Serial Attached SCSI, an evolution of parallel SCSI into a point-to-point 
serial peripheral interface in which controllers are linked directly to disk 
drives. SAS delivers improved performance over traditional SCSI 
because SAS enables up to 128 devices of different sizes and types to 
be connected simultaneously.
SATA
Serial ATA is a computer bus technology primarily designed for the 
transfer of data to and from hard disks and optical drives. SATA is the 
evolution of the legacy Advanced Technology Attachment (ATA) 
interface from a parallel bus to serial connection architecture.
SCSI
Small Computer System Interface, a parallel interface standard that 
provides faster data transmission rates than standard serial and parallel 
ports.
Session
A series of communications or exchanges of data between two end 
points that occurs during the span of a single connection. The session 
begins when the connection is established at both ends, and terminates 
when the connection is ended. For some applications each session is 
related to a particular port. In this document a session is the exchange 
of data between groups of primary and secondary volumes.
secondary volume (S-VOL)
A replica of the primary volume (P-VOL) at the time of a backup and is 
kept  on a standby storage system. Recurring differential data updates 
are performed to keep the data in the S-VOL consistent with data in the 
P-VOL. 
						

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SMTP
Simple Mail Transfer Protocol, a protocol used to receive and store 
email data directly from email servers.
Software initiator
A software application initiator communicates with a target device. A 
software initiator does not require specialized hardware because all 
processing is done in software, using standard network adapters.
Storage Navigator Modular 2
A multi-featured scalable storage management application that is used 
to configure and manage the storage functions of Hitachi arrays. Also 
referred to as Navigator 2.
Subnet
In computer networks, a subnet or subnetwork is a range of logical 
addresses within the address space that is assigned to an organization. 
Subnetting is a hierarchical partitioning of the network address space of 
an organization (and of the network nodes of an autonomous system) 
into several subnets. Routers constitute borders between subnets. 
Communication to and from a subnet is mediated by one specific port 
of one specific router, at least momentarily. SNIA.
Switch
A network infrastructure component to which multiple nodes attach. 
Unlike hubs, switches typically have internal bandwidth that is a 
multiple of link bandwidth, and the ability to rapidly switch node 
connections from one to another. A typical switch can accommodate 
several simultaneous full link bandwidth transmissions between 
different pairs of nodes. SNIA.
Target
Devices that receive iSCSI requests that originate from an iSCSI 
initiator.
TOE
A dedicated chip or adapter that handles much of the TCP/IP processing 
directly in hardware. TCP/IP transmission is inherently a CPU-intensive 
operation. Therefore, using dedicated hardware that can operate in 
parallel with the main processor allows for superior system 
performance. Although all iSCSI HBAs have a TOE, a generic TOE only 
implements TCP/IP, while an iSCSI HBA implements the iSCSI protocol 
in addition to TCP/IP.