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, comprising:
obtaining a base snapshot of the virtual disk;
implementing an input/output (I/O) filter framework to intercept an I/O stream between the VM and a virtualization server, wherein the I/O filter framework provides one or more configurable interception points of the I/O stream during an I/O lifecycle, and wherein the I/O stream comprises records of completed I/O requests and records of uncompleted I/O requests;
filtering the I/O stream to intercept, at a configured interception point of the one or more configurable interception points, only the records of completed I/O requests;
replicating, from among the records of completed I/O requests and the records of uncompleted I/O requests, the records of completed I/O requests at a backup site based at least on the filtering;
storing replicated versions of the records of completed I/O requests at the backup site in I/O logs based at least in part on the replicating;
forming a recoverable snapshot-log chain by applying the replicated versions of the records of completed I/O requests 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 , further comprising:
establishing a filter framework at the configured interception point, the filter framework including an I/O stack and an I/O filter.
3. The method of claim 2 , wherein the virtualization server is an ESX hypervisor server, and wherein the method further comprises:
including a filter driver for the filter framework within the ESX hypervisor server.
4. The method of claim 2 , further comprising:
configuring the filter framework to enable an I/O touch point in the I/O stream.
5. The method of claim 4 , wherein the I/O stream includes an I/O cancellation, and wherein the method further comprises:
configuring a filter driver to intercept only completed I/Os in the I/O stream using the I/O touch point.
6. The method of claim 5 , wherein the I/O cancellation is a distributed I/O cancellation, and wherein the method further comprises:
managing the distributed I/O cancellation at the I/O stack and not at the I/O filter of the filter framework.
7. A system for continuous data protection for a virtual machine (VM) having a virtual disk, the system comprising:
at least one processor; and
a memory storing machine-readable instructions executable by the at least one processor to cause the system to:
obtain a base snapshot of the virtual disk;
implement an input/output (I/O) filter framework to intercept an I/O stream between the VM and a virtualization server, wherein the I/O filter framework provides one or more configurable interception points of the I/O stream during an I/O lifecycle, and wherein the I/O stream comprises records of completed I/O requests and records of uncompleted I/O requests;
filter the I/O stream to intercept, at a configured interception point of the one or more configurable interception points, only the records of completed I/O requests;
replicate, from among the records of completed I/O requests and the records of uncompleted I/O requests, the records of completed I/O requests at a backup site based at least on the filtering;
store replicated versions of the records of completed I/O requests at the backup site in I/O logs based at least in part on the replicating;
form a recoverable snapshot-log chain by applying the replicated versions of the records of completed I/O requests stored in the I/O logs on top of the base snapshot;
receive a request for recoverable data from a replication target; and
send data to the replication target based at least on a portion of the recoverable snapshot-log chain.
8. The system of claim 7 , wherein the instructions are further configured to cause the at least one processor to cause the system to:
establish a filter framework at the configured interception point, the filter framework including an I/O stack and an I/O filter.
9. The system of claim 8 , wherein the virtualization server is an ESX hypervisor server, and wherein the instructions are further configured to cause the at least one processor to cause the system to:
include a filter driver for the filter framework within the ESX hypervisor server.
10. The system of claim 8 , wherein the instructions are further configured to cause the at least one processor to cause the system to:
configure the filter framework to enable an I/O touch point in the I/O stream.
11. The system of claim 10 , wherein the I/O stream includes an I/O cancellation, and wherein the instructions are further configured to cause the at least one processor to cause the system to:
configure a filter driver to intercept only completed Ms in the I/O stream using the I/O touch point.
12. The system of claim 11 , wherein the I/O cancellation is a distributed I/O cancellation, and wherein the instructions are further configured to cause the at least one processor to cause the system to:
manage the distributed I/O cancellation at the I/O stack and not at the I/O filter of the filter framework.
13. A non-transitory, machine-readable medium storing instructions for continuous data protection for a virtual machine (VM) having a virtual disk, wherein, when read by a machine, the instructions cause the machine to:
obtain a base snapshot of the virtual disk;
implement an input/output (I/O) filter framework to intercept an I/O stream between the VM and a virtualization server, wherein the I/O filter framework provides one or more configurable interception points of the I/O stream during an I/O lifecycle, and wherein the I/O stream comprises records of completed I/O requests and records of uncompleted I/O requests;
filter the I/O stream to intercept, at a configured interception point of the one or more configurable interception points, only the records of completed I/O requests;
replicate, from among the records of completed I/O requests and the records of uncompleted I/O requests, the records of completed I/O requests at a backup site based at least on the filtering;
store replicated versions of the records of completed I/O requests at the backup site in I/O logs based at least in part on the replicating;
form a recoverable snapshot-log chain by applying the replicated versions of the records of completed I/O requests stored in the I/O logs on top of the base snapshot;
receive a request for recoverable data from a replication target; and
send data to the replication target based at least on a portion of the recoverable snapshot-log chain.
14. The non-transitory, machine-readable medium of claim 13 , wherein, when read by the machine, the instructions cause the machine to:
establish a filter framework at the configured interception point, the filter framework including an I/O stack and an I/O filter.
15. The non-transitory, machine-readable medium of claim 14 , wherein the virtualization server is an ESX hypervisor server, and wherein, when read by the machine, the instructions cause the machine to:
include a filter driver for the filter framework within the ESX hypervisor server.
16. The non-transitory, machine-readable medium of claim 14 , wherein, when read by the machine, the instructions cause the machine to:
configure the filter framework to enable an I/O touch point in the I/O stream.
17. The non-transitory, machine-readable medium of claim 16 , wherein the I/O stream includes an I/O cancellation, and wherein, when read by the machine, the instructions cause the machine to:
configure a filter driver to intercept only completed I/Os in the I/O stream using the I/O touch point.
18. The non-transitory, machine-readable medium of claim 17 , wherein the I/O cancellation is a distributed I/O cancellation and wherein, when read by the machine, the instructions cause the machine to:
manage the distributed I/O cancellation at the I/O stack and not at the I/O filter of the filter framework.