Overland Storage REO 9000 - Manual (Page 11)

Reviewing REO 9000 Concepts and Requirements W 11
CHAPTER
1 Reviewing REO 9000 Concepts
and Requirements
The main steps involved in preparing to set up the REO Appliance
include:
Step 1 Understanding the concepts of iSCSI, Fibre Channel (FC), disk-to-disk-
to-tape (D2D2T) backup, redundant array of independent disks (RAID),
tape emulation, logical volume management (LVM), and how the REO
Appliance fits into the picture.
Step 2 Reviewing the requirements that your servers and network must meet to
ensure successful installation and operation of the REO Appliance.
Important Concepts to Understand
To understand the configuration of the backup network and how it fits
into the local-area network (LAN) or Fibre Channel (FC) storage-area
network (SAN), review the following sections.
Internet SCSI (iSCSI) Protocol
Internet SCSI (iSCSI) is a standard protocol for universal access to
shared storage devices over standard, Ethernet-based transmission
control protocol/Internet protocol (TCP/IP) networks. The connection-
oriented protocol transports SCSI commands, data, and status across an
IP network. For more information, see
Glossary and Acronym List on
page 163.
iSCSI Architecture
The iSCSI architecture is based on a client-server model. The client is a
host system that issues requests to read or write data. iSCSI refers to a
client as an initiator. The server is a resource that receives and executes
client requests. iSCSI refers to a server as a target.
File servers, which store the programs and data files shared by users,
normally play the role of server. With the REO Appliance, the application
and backup servers within your network act as clients or initiators and
the REO Appliance acts as a server or target. The initiators can either be
software drivers or iSCSI host bus adapters (HBAs) on the server that is
being backed up.