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Table Of Contents
2 Device drivers in the virtual machine’s operating system communicate with the virtual SCSI
controllers.
3 The virtual SCSI controller forwards the commands to the VMkernel.
4 The VMkernel performs the following tasks.
a Locates an appropriate virtual disk file in the VMFS volume.
b Maps the requests for the blocks on the virtual disk to blocks on the appropriate physical device.
c Sends the modified I/O request from the device driver in the VMkernel to the iSCSI initiator,
hardware or software.
5 If the iSCSI initiator is a hardware iSCSI adapter, independent or dependent, the adapter performs
the following tasks.
a Encapsulates I/O requests into iSCSI Protocol Data Units (PDUs).
b Encapsulates iSCSI PDUs into TCP/IP packets.
c Sends IP packets over Ethernet to the iSCSI storage system.
6 If the iSCSI initiator is a software iSCSI adapter, the following takes place.
a The iSCSI initiator encapsulates I/O requests into iSCSI PDUs.
b The initiator sends iSCSI PDUs through TCP/IP connections.
c The VMkernel TCP/IP stack relays TCP/IP packets to a physical NIC.
d The physical NIC sends IP packets over Ethernet to the iSCSI storage system.
7 Ethernet switches and routers on the network carry the request to the appropriate storage device.
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