Systems and methods for compacting a virtual machine file

A system for compacting a virtual machine file, the system comprising a physical computing system configured to:

• access a source virtual machine file associated with a guest file system;
• create a destination virtual machine file based on the guest file system;
• initialize a block allocation table of the destination virtual machine file;
• access a block allocation table of the source virtual machine file and for each block of the source virtual machine file identified in the block allocation table of the source virtual machine file:
• determine whether the block includes data that is not marked for deletion from the source virtual machine file;
• in response to determining that the block includes data that is not marked for deletion from the source virtual machine file, copy the block to the destination virtual machine file and update the block allocation table of the destination virtual machine file;
• and
• in response to determining either that the block does not include data or that the block includes data which is marked for deletion from the source virtual machine file, refrain from copying the block and refrain from updating the block allocation table of the destination virtual machine file, thereby reducing a size of the destination virtual machine file compared to a size of the source virtual machine file.

A system for compacting a virtual machine file, the system comprising:

• a physical host server comprising a virtualization layer configured to support a parent partition and one or more child partitions, the parent partition comprising a virtual machine management system and a compactor, the one or more child partitions each comprising a virtual machine associated with a guest operating system and one or more applications;
• a data store comprising one or more virtual machine files configured to be accessed by the one or more child partitions;
• and
• the compactor configured to:
• access, from the data store, a source virtual machine file comprising a dynamic virtual machine file and a guest file system;
• create a destination virtual machine file based, at least in part, on the guest file system, the destination virtual machine file comprising a dynamic virtual machine file;
• initialize a block allocation table of the destination virtual machine file;
• access a block allocation table of the source virtual machine file and for each block of the source virtual machine file identified in the block allocation table of the source virtual machine file:
• determining whether the block includes data that is not marked for deletion from the source virtual machine file;
• in response to determining that the block includes data that is not marked for deletion from the source virtual machine file, causing the block to be copied to the destination virtual machine file and updating the block allocation table of the destination virtual machine file;
• and
• in response to determining either that the block does not include data or that the block includes data which is marked for deletion from the source virtual machine file, not causing the block to be copied and not updating the block allocation table of the destination virtual machine file thereby reducing a size of the destination virtual machine file compared to a size of the source virtual machine file.

Non-transitory computer storage configured to store executable instructions that when executed by a processor cause the processor to:

• access a source virtual machine file comprising a dynamic virtual machine file associated with a guest file system;
• determine the guest file system associated with the source virtual machine file;
• create a destination virtual machine file based on the guest file system, the destination virtual machine file comprising a dynamic virtual machine file;
• initialize a block allocation table of the destination virtual machine file;
• access a block allocation table of the source virtual machine file and for each block of the source virtual machine file identified in the block allocation table of the source virtual machine file:
• determine whether the block includes data that is not marked for deletion from the source virtual machine file;
• in response to determining that the block includes data that is not marked for deletion from the source virtual machine file, copy the block to the destination virtual machine file and update the block allocation table of the destination virtual machine file;
• and
• in response to determining either that the block does not include data or that the block includes data which is marked for deletion from the source virtual machine file, not copy the block and not update the block allocation table of the destination virtual machine file thereby reducing a size of the destination virtual machine file compared to a size of the source virtual machine file.