which two tasks are performed by VMKernel?

When using a hardware iSCSI initiator with an ESXi host, which two tasks are performed by VMKernel? (Choose two)

A.
Encapsulation of iSCSI PDUs TCP/IP packets

B.
Mapping requests for blocks on the virtual disk to blocks on the appropriate physical device

C.
Issuing SCSS commands to the virtual disk

D.
Encapsulation of I/O requests into iSCSI Protocol Data Units (PDUs)

Explanation:
Using HW iSCSI adapter it will offload from the VMkernel to the HW iSCSI adapter:

Encapsulation of iSCSI PDUs TCP/IP packets
and
Encapsulation of I/O requests into iSCSI Protocol Data Units (PDUs)

Hence the VMkernel does not perform these two tasks making these the correct answers:

Mapping requests for blocks on the virtual disk to blocks on the appropriate physical device
and
Issuing SCSS commands to the virtual disk

Page 68 from vsphere-esxi-vcenter-server-50-storage-guide.pdf

4 Comments on “which two tasks are performed by VMKernel?

  1. Clay says:

    CORRECTION
    So I re-read the question after I posted.. Its asks what is done by the VMkernel not Adapter, this is why I get questions wrong on the test, shooting by the hip

    Should be B ONLY

    A – done by adapter
    B – done by VMkernel
    C – done by VM
    D – done by adapter

  2. azverev says:

    correct answer is B,C

    2 Clay ,

    about answer C,

    lets take a look how it works in physical server:
    OS is issuing scsi commands to controller (using device driver) after that hardware controller issuing commands to disk or array of disks,

    in VM we have no hardware devices such as ethernet adapters and hardware controllers, their tasks perfomed by VMkernel( Intel network cards,LSI SAS controller)


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