Saving virtual memory space in a clone environment

A computer system for saving virtual memory space in a clone environment, the computer system comprising:

• a processor;
• and
• a non-transitory computer readable medium having stored thereon program code, the program code causing the processor to:
• create a first clone virtual machine (VM) of a first parent VM on a computing node, the first parent VM and the first clone VM forming a first VM chain;
• define a first deduplication ID for the first VM chain;
• create a first plurality of additional clone VMs from the first parent VM, the first plurality of additional clone VMs being within the first VM chain;
• generate, for each of the VMs in the first VM chain, a logical addressing table linked to the first deduplication ID, the logical addressing table having a plurality of entries that point to a same block on a storage medium;
• generate, for the first VM chain, a chain hash table and share the chain hash table across all VMs in the first VM chain;
• based at least on a swap out request for writing a block of memory to the storage medium, received from one of the VMs in the first VM chain, generate a hash value for the block of memory to be written to the storage medium;
• based at least on finding the hash value within the shared chain hash table, update the logical addressing table for the one of the VMs in the first VM chain to indicate a location of a prior-existing duplicate of the block on the storage medium;
• and
• based at least on not finding the hash value within the shared chain hash table:
• write the block to the storage medium;
• update the logical addressing table for the one of the VMs in the first VM chain to indicate a location of the block on the storage medium;
• and
• update the shared chain hash table with the hash value.

One or more non-transitory computer storage media having computer-executable instructions that, upon execution by a processor, cause the processor to at least perform operations that comprise:

• creating a first clone virtual machine (VM) of a first parent VM on a computing node, the first parent VM and the first clone VM forming a first VM chain;
• defining a first deduplication ID for the first VM chain;
• creating a first plurality of additional clone VMs from the first parent VM, the first plurality of additional clone VMs being within the first VM chain;
• generating, for each of the VMs in the first VM chain, a logical addressing table linked to the first deduplication ID, the logical addressing table having a plurality of entries that point to a same block on a storage medium;
• generating, for the first VM chain, a chain hash table and sharing the chain hash table across all VMs in the first VM chain;
• based at least on a swap out request for writing a block of memory to the storage medium, received from one of the VMs in the first VM chain, generating a hash value for the block of memory to be written to storage medium;
• based at least on finding the hash value within the shared chain hash table, updating the logical addressing table for the one of the VMs in the first VM chain to indicate a location of a prior-existing duplicate of the block on the storage medium;
• and
• based at least on not finding the hash value within the shared chain hash table:
• writing the block to the storage medium;
• updating the logical addressing table for the one of the VMs in the first VM chain to indicate a location of the block on the storage medium;
• and
• updating the shared chain hash table with the hash value.