Data consistency between virtual machines

摘要

Data consistency between a primary virtual machine and a recovery virtual machine may employ a resync engine to detect differences in data blocks stored on both virtual machines. For example, the resync engine may calculate a signature (e.g., hash value) for a primary data block and a corresponding signature for a recovery data block, and compare the signature and the corresponding signature to identify a difference between the primary data block and the recovery data block. In some instances, by identifying a difference between the primary data block and the recovery data block, a data block (e.g., primary data block or recovery data block) may be identified to be transferred from a virtual machine to another virtual machine.

主权项

1. A system, comprising:
one or more processors; and memory, communicatively coupled to the one or more processors, storing one or more modules that are executable by the one or more processors to perform acts comprising: receiving one or more first data blocks from a primary virtual hard disk; sending the one or more first data blocks to a first buffer; receiving, after a time period has expired since the one or more first data blocks were sent to the first buffer, the one or more first data blocks from the first buffer;
calculating a first data signature for at least a portion of a data block of the one or more first data blocks;sending the first data signature to a second buffer; receiving the first data signature from the second buffer after a time period has expired since the first data signature was sent to the second buffer; in response to receiving the first data signature from the second buffer, requesting a second data signature from a recovery virtual machine, the second data signature representing one or more second data blocks corresponding to the one or more first data blocks; receiving the second data signature from the recovery virtual machine; comparing the first data signature with the second data signature; determining that the one or more first data blocks and the one or more second data blocks are different based, at least in part, on the comparison; and causing, at least partly in response to the determining that the one or more first data blocks and the one or more second data blocks are different, the one or more first data blocks to be sent from the primary virtual hard disk to the recovery virtual machine.