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number of storage volumes by using iSCSI over TCP/IP networks. IP SANs
can scale the storage capacity with any type and brand of storage system. In
addition, it can be used by any type of network (Ethernet, Fast Ethernet, and
Gigabit Ethernet) and combination of operating systems (Microsoft Windows,
Linux, Solaris, etc.) within the SAN network. IP-SANs also include
mechanisms for security, data replication, multi-path and high availability.
Storage protocol, such as iSCSI, has “two ends” in the connection. These
ends are initiator and target. In iSCSI, we call them iSCSI initiator and iSCSI
target. The iSCSI initiator requests or initiates any iSCSI communication. It
requests all SCSI operations like read or write. An initiator is usually located
on the host/server side (either an iSCSI HBA or iSCSI SW initiator).
The target is the storage device itself or an appliance which controls and
serves volumes or virtual volumes. The target is the device which executes
SCSI commands or plays a role as the bridge to an attached storage device.
Figure 2.2.1
The host side needs an iSCSI initiator. The initiator is a driver which handles
the SCSI traffic over iSCSI. The initiator can be software or hardware (HBA).
iSCSI device 1
(target)
Host 1
(initiator)
NIC
IP SAN
Host 2
(initiator)
iSCSI
HBA
iSCSI device 2
(target)
