Systems and methods for continuous data protection
Example embodiments relate generally to systems and methods for continuous data protection (CDP) and more specifically to an input and output (I/O) filtering framework and log management system to seek a near-zero recovery point objective (RPO).
1. A method for continuous data protection for a virtual machine (VM) having a virtual disk, the method comprising at least the following operations:
identifying a base snapshot of the virtual disk;
intercepting, at an interception point in an I/O path, a virtual disk I/O stream between the VM and a virtualization server, the I/O stream including an I/O start, an I/O completion, and an I/O cancellation;
establishing a filter framework at the interception point, the filter framework including an I/O stack and a configurable I/O filter, the configurable I/O filter being configurable to provide a selectable touchpoint for interception and replication of the I/O stream;
based on a selected touchpoint, filtering out from interception and replication, an I/O cancellation occurring between the I/O start and the I/O completion;
replicating the I/O stream at a backup site;
storing the replicated I/O stream at the backup site in I/O logs;
forming a recoverable snapshot-log chain by applying the replicated I/O stream stored in the I/O logs on top of the base snapshot;
receiving a request for recoverable data from a replication target; and
sending data to the replication target based at least on a portion of the recoverable snapshot-log chain.
2. The method of claim 1 , wherein the virtualization server is an ESX hypervisor server and the operations further comprise including a filter driver for the filter framework within the ESX hypervisor server.
3. The method of claim 1 , wherein the I/O cancellation is a distributed I/O cancellation and wherein the operations further comprise managing the distributed I/O cancellation at the I/O stack and not at the I/O filter of the filter framework.
4. A system for continuous data protection for a virtual machine (VM) having a virtual disk, the system comprising:
at least one processor for executing machine-readable instructions; and
a memory storing instructions configured to cause the at least one processor to perform operations comprising, at least:
identifying a base snapshot of the virtual disk;
intercepting, at an interception point in an I/O path, a virtual disk I/O stream between the VM and a virtualization server, the I/O stream including an I/O start, an I/O completion, and an I/O cancellation;
establishing a filter framework at the interception point, the filter framework including an I/O stack and a configurable I/O filter, the configurable I/O filter being configurable to provide a selectable touchpoint for interception and replication of the I/O stream;
based on a selected touchpoint, filtering out from interception and replication, an I/O cancellation occurring between the I/O start and the I/O completion;
replicating the I/O stream at a backup site;
storing the replicated I/O stream at the backup site in I/O logs;
forming a recoverable snapshot-log chain by applying the replicated I/O stream stored in the VO logs on top of the base snapshot;
receiving a request for recoverable data from a replication target; and
sending data to the replication target based at least on a portion of the recoverable snapshot-log chain.
5. The system of claim 3 , wherein the virtualization server is an ESX hypervisor server and the operations further comprise including a filter driver for the filter framework within the ESX hypervisor server.
6. The system of claim 3 , wherein the I/O cancellation is a distributed I/O cancellation and wherein the operations further comprise managing the distributed I/O cancellation at the I/O stack and not at the I/O filter of the filter framework.
7. A non-transitory, machine-readable medium storing instructions which, when read by a machine, cause the machine to perform operations in a method for continuous data protection for a virtual machine (VM) having a virtual disk, the operations comprising, at least:
identifying a base snapshot of the virtual disk;
intercepting, at an interception point in an I/O path, a virtual disk I/O stream between the VM and a virtualization server, the I/O stream including an I/O start, an I/O completion, and an I/O cancellation;
establishing a filter framework at the interception point, the filter framework including an I/O stack and a configurable I/O filter, the configurable I/O filter being configurable to provide a selectable touchpoint for interception and replication of the I/O stream;
based on a selected touchpoint, filtering out from interception and replication, an I/O cancellation occurring between the I/O start and the I/O completion;
replicating the I/O stream at a backup site;
storing the replicated I/O stream at the backup site in I/O logs;
forming a recoverable snapshot-log chain by applying the replicated I/O stream stored in the I/O logs on top of the base snapshot;
receiving a request for recoverable data from a replication target; and
sending data to the replication target based at least on a portion of the recoverable snapshot-log chain.
8. The medium of claim 7 , wherein the virtualization server is an ESX hypervisor server and the operations further comprise including a filter driver for the filter framework within the ESX hypervisor server.
9. The medium of claim 7 , wherein the I/O cancellation is a distributed I/O cancellation and wherein the operations further comprise managing the distributed I/O cancellation at the I/O stack and not at the I/O filter of the filter framework.