Ensuring storage availability for virtual machines

A non-transitory computer readable storage medium having stored thereon computer readable program code for allocating storage for a virtual disk of a virtual machine configured to execute on a first host computer, where the first host computer is associated with a plurality of data storage devices including first and second data storage devices, and where a first portion of storage is allocated to the virtual disk from the first storage device, the computer readable program code comprising:

• computer readable program code to receive a request to allocate a second portion of storage to the virtual disk of the virtual machine;
• computer readable program code to, in response to determining that the first data storage device has insufficient free storage space from which to allocate the second portion of storage, select the second data storage device having sufficient free storage space from which to allocate the second portion of storage;
• and
• computer readable program code to allocate the second portion of storage for the virtual disk of the virtual machine from the second data storage device, wherein the virtual machine accesses the first and second portions of storage as a single virtual disk.

A virtualized computing system, comprising:

• a first host computer with a virtual machine executing therein;
• a plurality of data storage devices including first and second data storage devices that are associated with the first host computer, wherein a first portion of storage is allocated to the virtual disk from the first storage device;
• and
• a management server configured to allocate storage for the virtual disk of the virtual machine, wherein the management server is configured to:
• receive a request to allocate a second portion of storage to the virtual disk of the virtual machine;
• in response to determining that the first data storage device has insufficient free storage space from which to allocate the second portion of storage, select the second data storage device having sufficient free storage space from which to allocate the second portion of storage;
• and
• allocate the second portion of storage for the virtual disk of the virtual machine from the second data storage device, wherein the virtual machine accesses the first and second portions of storage as a single virtual disk.