vCloud Director and vRAM Datastore usage

Scenario:

VDC Storage Allocation = 120GB

1 VAPP with 2 virtual machines

4GB of RAM in each and a 40GB Disk per VM.

Total disk usage – 8OGB right?

Customer attempts to create a new VM with exactly the same specs as above, (4GB of RAM and 40GB disk) they are told that they will exceed there storage allocation!

The customer checked their storage usage and vCloud Director reports that they are using 88GB of their 120GB allocation, they have no templates in their catalog so cannot understand where the extra 8GB of storage has gone???

Explanation:

Whatever the size of the virtual machine memory, vCloud Director will reserve the equivalent data store space for the swapfile, so a virtual machine with 4GB of RAM will consume 4GB of disk space on the datastore.

vCloud Director does not take into account memory reservations, it effectively treats it as 100% memory reservation.  This is also irrespective of the power state of the virtual machine.

Memory of virtual machines stored in the catalog is not included in the space allocation.

Something worth taking into conisderation when sizing vCloud Director implementations!

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