Method and system for enabling data backups for virtual machines reliant on raw device mapping disks
A method and system for enabling data backups for virtual machines reliant on raw data mapping (RDM) disks to store their state and/or data. Traditional virtual machine backup methodologies pivot on the generation and storage of virtual machine snapshots as copies of a virtual machine disk file, which store the state and/or data of a virtual machine at various given points in time. However, these traditional virtual machine backup methodologies, at least at present, do not support the generation and storage of virtual machine snapshots for virtual machines that particularly access and consolidate information on RDM disks. Accordingly, the method and system disclosed herein facilitate the backup of state and/or data pertaining to virtual machines reliant on RDM disks.
1. A method for backing up virtual machines, comprising:
selecting, from an already distributed buffer (ADB), an already distributed entry (ADE) comprising a virtual machine snapshot, wherein the ADE is one of a plurality of ADEs that have been distributed and stored in the ADB;
identifying a replica disk to which the virtual machine snapshot has been distributed, wherein the replica disk is one selected from a group consisting of a raw device mapping (RDM) formatted disk and a virtual machine disk (VMDK) formatted disk;
identifying a consistency group (CG) comprising at least the replica disk;
setting an access mode for the CG to a logged-access mode, wherein the logged-access mode suspends distribution and grants access to the CG;
deactivating a replica virtual machine (RVM) operatively connected to the replica disk;
restoring the virtual machine snapshot to obtain a logical volume, wherein the logical volume comprises a temporary disk partition to recover written data from the virtual machine snapshot; and
backing up the logical volume using a proxy virtual machine (PVM).
2. The method of claim 1 , wherein the virtual machine snapshot comprises a write copy of a write from a source virtual machine (SVM) to a source RDM disk.
3. The method of claim 2 , wherein the RVM is a backup virtual machine for the SVM, wherein the replica disk is a backup disk for the source RDM disk.
4. The method of claim 1 , wherein the logical volume is hosted by the replica disk.
5. The method of claim 1 , wherein backing up the logical volume using the PVM comprises:
attaching the logical volume to the PVM;
instructing the PVM to replicate the logical volume to obtain a replicated logical volume, wherein upon completing replication of the logical volume, the PVM transmits the replicated logical volume to a third-party storage system; and
detaching the logical volume from the PVM.
6. The method of claim 1 , further comprising:
after backing up the logical volume:
recycling the logical volume;
setting the access mode for the CG to a no-access mode; and
reactivating the RVM operatively connected to the replica disk.
7. The method of claim 1 , further comprising:
prior to selecting, from the ADB, the ADE comprising the virtual machine snapshot:
receiving the virtual machine snapshot from a production site;
generating a waiting distribution entry (WDE) using at least the virtual machine snapshot; and
queuing the WDE at a top of a waiting distribution buffer (WDB).
8. The method of claim 7 , further comprising:
when the WDE reaches a bottom of the WDB after being queued at the top of the WDB:
obtaining the virtual machine snapshot from the WDE;
writing the virtual machine snapshot to the replica disk;
repurposing the WDE as the ADE; and
recording the ADE in the ADB.
9. A system, comprising:
a first computer processor;
a proxy virtual machine (PVM) executing on the first computer processor; and
a remote continuous replication agent (CRA) operatively connected to the PVM, and programmed to:
select, from an already distributed buffer (ADB), an already distributed entry (ADE) comprising a virtual machine snapshot, wherein the ADE is one of a plurality of ADEs that have been distributed and stored in the ADB;
identify a replica disk to which the virtual machine snapshot has been distributed, wherein the replica disk is one selected from a group consisting of a raw device mapping (RDM) formatted disk and a virtual machine disk (VMDK) formatted disk;
identify a consistency group (CG) comprising at least the replica disk;
set an access mode for the CG to a logged-access mode, wherein the logged-access mode suspends distribution and grants access to the CG;
deactivate a replica virtual machine (RVM) operatively connected to the replica disk;
restore the virtual machine snapshot to obtain a logical volume, wherein the logical volume comprises a temporary disk partition to recover written data from the virtual machine snapshot; and
back up the logical volume using the PVM.
10. The system of claim 9 , wherein the remote CRA is one selected from a group consisting of a computing appliance comprising a second computer processor and a computer program executing on the first computer processor.
11. The system of claim 9 , further comprising:
a third-party storage system operatively connected to the PVM.
12. The system of claim 9 , further comprising:
a remote computing system (RCS) comprising the remote CRA, the PVM, and a set of RVMs comprising the RVM.
13. The system of claim 12 , further comprising:
a remote storage system (RSS) operatively connected to the RCS and comprising a remote journal volume (RJV) and a set of replica disks,
wherein the RJV comprises the ADB and the set of replica disks comprises the replica disk.
14. The system of claim 9 , further comprising:
a production computing system (PCS) comprising a set of source virtual machines (SVMs) and a production CRA,
wherein the RVM is a backup virtual machine for a SVM of the set of SVMs,
wherein the production CRA is operatively connected to the remote CRA.
15. The system of claim 14 , further comprising:
a production storage system (PSS) operatively connected to the PCS and comprising a production journal volume (PJV) and a set of source RDM disks,
wherein the replica disk is a backup disk for a source RDM disk of the set of source RDM disks.
16. A non-transitory computer readable medium (CRM) comprising computer readable program code, which when executed by a computer processor, enables the computer processor to:
select, from an already distributed buffer (ADB), an already distributed buffer entry (ADE) comprising a virtual machine snapshot, wherein the ADE is one of a plurality of ADEs that have been distributed and stored in the ADB;
identify a replica disk to which the virtual machine snapshot has been distributed, wherein the replica disk is one selected from a group consisting of a raw device mapping (RDM) formatted disk and a virtual machine disk (VMDK) formatted disk;
identify a consistency group (CG) comprising at least the replica disk;
set an access mode for the CG to a logged-access mode, wherein the logged-access mode suspends distribution and grants access to the CG;
deactivate a replica virtual machine (RVM) operatively connected to the replica disk;
restore the virtual machine snapshot to obtain a logical volume, wherein the logical volume comprises a temporary disk partition to recover written data from the virtual machine snapshot; and
back up the logical volume using a proxy virtual machine (PVM).
17. The non-transitory CRM of claim 16 , wherein to back up the logical volume using the PVM, the computer readable program code, which when executed by the computer processor, enables the computer processor to:
attach the logical volume to the PVM;
instruct the PVM to replicate the logical volume to obtain a replicated logical volume, wherein upon completing replication of the logical volume, the PVM transmits the replicated logical volume to a third-party storage system; and
detach the logical volume from the PVM.
18. The non-transitory CRM of claim 16 , further comprising computer readable program code, which when executed by the computer processor, enables the computer processor to:
after backing up the logical volume:
recycle the logical volume;
set the access mode for the CG to a no-access mode; and
reactivate the RVM operatively connected to the replica disk.
19. The non-transitory CRM of claim 16 , further comprising computer readable program code, which when executed by the computer processor, enables the computer processor to:
prior to selecting, from the ADB, the ADE comprising the virtual machine snapshot:
receive the virtual machine snapshot from a production site;
generate a waiting distribution entry (WDE) using at least the virtual machine snapshot; and
queue the WDE at a top of a waiting distribution buffer (WDB).
20. The non-transitory CRM of claim 19 , further comprising computer readable program code, which when executed by the computer processor, enables the computer processor to:
when the WDE reaches a bottom of the WDB after being queued at the top of the WDB:
obtain the virtual machine snapshot from the WDE;
write the virtual machine snapshot to the replica disk;
repurpose the WDE as the ADE; and
record the ADE in the ADB.