Holy VMFS3 Batman!

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“Robin, go carve me out a new LUN for our new Batworks Monitoring System!”, says Batman.  Robin replies, “It is ready for you Batman, let’s get monitoring the Batwork.”


My P2V has failed…“Failed to create virtual disk: There is not enough space on the file system for the selected operation.” What will Gotham do now!?!?

I am sure that many of you have run into the issue where your Storage Guy gives you a new LUN and you create a VMFS datastore and find out you somehow don’t have enough space.  Although, you know for fact that you were given 1TB or more on the LUN.  What happened?

Well, a lot of people tend to click right on through accepting any and all defaults that are presented to you.  One thing you missed was the wonderful block size selection.  You are presented with the Disk/LUN Formatting section and you see you actually had choices you could make:  small (1MB), medium (2MB), large (4MB), and super size (8MB).

If you were presented with 1TB then you would need to make sure that you select the appropriate block size to enable the use of that ever-so-expensive disk space.  For example-sake, if you need to provision a VMFS datastore of a size less than 256GB you need to select 1MB blocks, if you need to provision 512GB then use 2MB blocks, 1TB would require at least 4MB blocks, and 2TB requires 8MB blocks.

Now one asks, “Why and what causes this?”

The answer is simple…filesystem limitations of VMFS3.  Word has it that VMFS4 will not have these limitations.  It will supposedly follow ext4 limitations which enable 16TB.  Sound off in the comments regarding your thoughts and experiences with VMFS3 and the future of VMFS!

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