iSCSI Storage
OverviewLast Updated December 16, 2024
With iSCSI, SCSI
storage commands that your virtual machine issues to its virtual disk are
converted into TCP/IP protocol packets and transmitted to a remote device, or
target, on which the virtual disk is located. To the virtual machine, the
device appears as a locally attached SCSI drive.
To access remote targets, the
ESXi
host uses
iSCSI initiators. Initiators transport SCSI requests and responses between
ESXi
and the
target storage device on the IP network.
ESXi
supports
the following types of initiators.
- Software iSCSI adapter - VMware code built into the VMkernel. Allows anESXihost to connect to the iSCSI storage device through standard network adapters. The software initiator handles iSCSI processing while communicating with the network adapter.
- Hardware iSCSI adapter - Offloads all iSCSI and network processing from your host. Hardware iSCSI adapters are broken into two types.
- Dependent hardware iSCSI adapter - Leverages the VMware iSCSI management and configuration interfaces.
- Independent hardware iSCSI adapter - Leverages its own iSCSI management and configuration interfaces.
See the
vSphere Storage
documentation for details on setup and failover scenarios.
You must configure iSCSI
initiators for the host to access and display iSCSI storage devices.
Figure 1
depicts hosts that use different types of iSCSI initiators.
- The host on the left uses an independent hardware iSCSI adapter to connect to the iSCSI storage system.
- The host on the right uses software iSCSI.
Dependent hardware iSCSI can be
implemented in different ways and is not shown. iSCSI storage devices from the
storage system become available to the host. You can access the storage devices
and create VMFS datastores for your storage needs.
iSCSI Storage
