iSCSI (Internet Small Computer System Interface) encapsulates SCSI control and data in TCP/IP packets, allowing access to storage devices over the existing network infrastructure. An iSCSI SAN usually consists of the following components:
- iSCSI storage system – a physical storage system on the network.
- LUN (Logical Unit Number) – a number used to identify a device addressed by the iSCSI protocol.
- iSCSI target – a logical target-side device that hosts iSCSI LUNs and masks to specific iSCSI initiators. An iSCSI target receives SCSI commands from the iSCSI initiator over the IP network.
- iSCSI initiator – a logical host-side device that transmits SCSI commands to iSCSI target over the IP network. An iSCSI initiator resides on the ESXi host.
- iSCSI Network Portal – IP addresses used by an iSCSI initiator or iSCSI target.
- iSCSI Qualified Name (IQN) – the unique identifier for an iSCSI initiator, target, or LUN.
- iSCSI Naming Service (iSNS) – a protocol that allows automated discovery, management and configuration of iSCSI devices on an IP network. Rarely used today.
The following picture gives you an overview of iSCSI components (source: VMware):
- Good low light camera
- Water resistant
- Double the internal capacity
- Lacks clear upgrades
- Same design used for last three phones
- Battery life unimpressive