What is one requirement when adding an extent to a VMFS datastore?

What is one requirement when adding an extent to a VMFS datastore?

A.
A new unused NFS mount

B.
An RDM with sufficient space available

C.
An unused iSCSI or FCP LUN

D.
Free space on the LUN holding the VMFS datastore

10 Comments on “What is one requirement when adding an extent to a VMFS datastore?

  1. Scott says:

    Admin: just taking a moment to thank you for this site. I passed my VCP on friday, and wanted to thank you and others for maintaining and keeping this site up and running! Much appreciated! Good Luck to the rest of you planning on sitting the exam. It wasn’t as easy as I expected it to be, but alas I still passed and you can too! Good Luck People!

  2. lx4svr says:

    The Answer is C not D

    D is the answer for growing an Extent, but the question is for adding an extent.

    When adding an extent you should use a new LUN and one from the same storage device that the current VMFS datastore uses, for VMFS locks the entire LUN and not just a partition, and the same storage device should be used due to the fact that if the LUNs have different speeds, then it will most likely cause performance issues.

    When growing an extent so that it fills up its capacity, only extent with free space after them can be expanded.

  3. vcp510 says:

    The current size limit for a VMFS extent is 2TB-512B. For large VMFS volumes, you must use spanning to concatenate multiple 2TB-512B extents. An extent is a partition on a storage device or LUN. As there is currently a limit of 32 extents in a VMFS volume, the size limit on any VMFS volume is 64TB. Spanning of multiple volumes (LUNs) is required to reach that upper limit and is needed for any VMFS volume that is greater than 2TB in size. For more information on the size limits, see the Configuration Maximums guide.

    For large VMFS volumes, use one of these methods:
    • Add a new extent. The spanned VMFS datastore can use any of all its extents at any time. It does not need to fill up a particular extent before using the next one.
    • Grow an extent in an existing VMFS datastore so that it fills the available adjacent capacity. Only extents with free space immediately after them are expandable. This can only be done on a LUN with size limit 2TB-512B.


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