iSCSI transfers data in block units. An IP-SAN that uses an existing Ethernet can be constructed by using iSCSI. An iSCSI network provides the following features:
- Connecting multiple hosts to an iSCSI port:
You can connect more than one host to a port on your storage system.
When setting up host connections, for each host you specify the settings for host mode, volume, and iSCSI target. Each host can access a volume simulating a dedicated port to the host even if that host shares the port with other hosts.
- Mapping volumes to hosts:
You can map or assign volumes to the hosts on your network. You have complete flexibility to share or restrict volume access among the hosts.
- Network security:
You can enable or disable CHAP (Challenge Handshake Authentication Protocol), a security protocol that requires users to enter a secret for access.
The following are iSCSI functions:
- The iSCSI security control function controls the access from specific hosts or specific commands.
- The iSCSI target function enables the storage system to respond to each connected host, even within the same port, by grouping the connected hosts within a port and setting LUs and host mode options for each group. You can set up to 255 iSCSI targets per port. Authentication can be performed for each target by using the CHAP authentication concurrently.
The iSCSI ports do not support fragment processing (dividing a packet). When the maximum transmission unit (MTU) of a switch is smaller than that of an iSCSI port, packets might be lost, and data cannot be transferred correctly. The MTU value for the switch must be the same as or greater than the MTU value for the iSCSI port. For details about the MTU setting and value, see the user documentation for the switch.