# US 2014/0195848 A1 · Methods and systems for instant restore of system volume > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0195848 A1 - Document ID: US20140195848A1 - Status: Published application - Kind: A1 - Application number: 13/736,716 - Filed: 2013-01-08 - Published: 2014-07-10 - Earliest claimed: 2013-01-08 - Assignees: Symantec Corporation - Applicants: Symantec, Inc. - Inventors: Ravindra V. TELI; Mohammad Eliyas SHAIKH; Chirag DALAL - Web page: https://patentgrep.com/patent/US20140195848A1 ## CPC - G06F 11/1469: {Backup restoration techniques} - G06F 11/1417: {Boot up procedures} - G06F 2201/815: Virtual - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Techniques are disclosed for restoring a system volume on a computing system without requiring the system volume to be fully restored prior to being used or requiring the use of a dedicated recovery environment (e.g., the WinPE or BartPE environments). Instead, the computing system is booted directly from the restore image or by redirecting I/O interrupts to the restore image. That is, when user initiates a restore process, the system boots from the backup itself. Once booted, a background process can complete the restore process. ## Claims ### Claim 1 A computer-implemented method for restoring a system volume on a computing system from a network restore volume, the method comprising: receiving an indication to restore the system volume from the network restore volume launching a network boot loader configured to perform disk I/O on the computing system, wherein the network boot loader is configured to load an operating system by performing read operations by reading from the network restore volume; and after the boot loader turns over control for disk I/O to the loaded operating system, launching a volume filter driver configured to perform read operations directed to the system volume from the network restore volume and to perform write operations by writing to the system volume. ### Claim 2 (depends on 1) The method of claim 1, wherein the volume filter driver is configured to complete restoring the system volume from the network restore volume by copying disk sectors from the network restore volume to the system volume. ### Claim 3 (depends on 2) The method of claim 2, further comprising, after restoring the system volume, transitioning the disk filter driver to a pass through mode which directs disk I/O read and write requests to the restored system volume. ### Claim 4 (depends on 1) The method of claim 1, wherein the network boot loader is configured to mount the system volume and redirect an interrupt associated with disk I/O to a redirector function configured to perform the read operations directed to the system volume by reading from the network restore volume and to perform the write operations by writing to the system volume. ### Claim 5 (depends on 1) The method of claim 1, wherein the network restore volume is stored in a virtual hard disk (VHD). ### Claim 6 (depends on 5) The method of claim 5, wherein the network restore volume is exposed to the computing system as a block device. ### Claim 7 A computer-implemented method for restoring a system volume on a computing system from a network restore volume, the method comprising: receiving an indication to restore the system volume from the network restore volume; launching a network boot loader configured to perform disk I/O on the computing system, wherein the network boot loader is configured to mount the network restore volume, and wherein the network restore volume is stored in a parent virtual hard disk (VHD) and differencing VHD, and wherein read operations are performed by reading from the parent VHD and wherein write operations are accumulated in the differencing VHD; and after the boot loader turns over control for disk I/O to an operating system loaded from the network restore volume, launching a filter driver configured to restore the system volume by copying blocks from the mounted network restore volume. ### Claim 8 (depends on 7) The method of claim 7, further comprising, after restoring the system volume, transitioning the volume filter driver to a redirect mode which redirects disk I/O read and write requests to the restored system volume. ### Claim 9 (depends on 7) The method of claim 7, wherein the network restore volume is exposed to the computing system as a block device. ### Claim 10 A computer-readable storage medium storing instructions, which, when executed on a processor, perform an operation for restoring a system volume on a computing system from a network restore volume, the operation comprising: receiving an indication to restore the system volume from the network restore volume launching a network boot loader configured to perform disk I/O on the computing system, wherein the network boot loader is configured to load an operating system by performing read operations by reading from the network restore volume and by performing write operations by writing to the system volume being restored; and after the boot loader turns over control for disk I/O to the loaded operating system, launching a volume filter driver configured to perform read operations directed to the system volume from the network restore volume and to perform write operations by writing to the system volume. ### Claim 11 (depends on 10) The computer-readable storage medium of claim 10, wherein the volume filter driver is configured to complete restoring the system volume from the network restore volume by copying disk sectors from the network restore volume to the system volume. ### Claim 12 (depends on 11) The computer-readable storage medium of claim 11, wherein the operation further comprises, after restoring the system volume, transitioning the disk filter driver to a pass through mode which directs disk I/O read and write requests to the restored system volume. ### Claim 13 (depends on 10) The computer-readable storage medium of claim 10 wherein the network boot loader is configured to mount the system volume and redirect an interrupt associated with disk I/O to a redirector function configured to perform the read operations directed to the system volume by reading from the network restore volume and to perform the write operations by writing to the system volume. ### Claim 14 (depends on 10) The computer-readable storage medium of claim 10, wherein the network backup image is stored in a virtual hard disk (VHD). ### Claim 15 (depends on 14) The computer-readable storage medium of claim 14, wherein the network backup image is exposed to the computing system as a block device. ### Claim 16 A computer-readable storage medium storing instructions, which, when executed on a processor, perform an operation for restoring a system volume on a computing system from a network restore volume, the operation comprising: receiving an indication to restore the system volume from the network backup image; launching a network boot loader configured to perform disk I/O on the computing system, wherein the network boot loader is configured to mount the network restore volume, and wherein the network restore volume is stored in a parent virtual hard disk (VHD) and differencing VHD, and wherein read operations are performed by reading from the parent VHD and wherein write operations are accumulated in the differencing VHD; and after the boot loader turns over control for disk I/O to an operating system loaded from the network restore volume, launching a volume filter driver configured to restore the system volume by copying blocks from the mounted network restore volume. ### Claim 17 (depends on 16) The computer-readable storage medium of claim 16, wherein the operation further comprises, after restoring the system volume, transitioning the volume filter driver to a redirect mode which redirects disk I/O read and write requests from the mounted network restore volume to the restored system volume. ### Claim 18 (depends on 16) The computer-readable storage medium of claim 16, wherein the network backup image is exposed to the computing system as a block device. ### Claim 19 A system, comprising: a processor; and a memory storing code, which, when executed on the processor, performs an operation for restoring a system volume on a computing system from a network restore volume, the operation comprising: receiving an indication to restore the system volume from the network restore volume, launching a network boot loader configured to perform disk I/O on the computing system, wherein the network boot loader is configured to load an operating system by performing read operations by reading from the network restore volume d, and after the boot loader turns over control for disk I/O to the loaded operating system, launching a volume filter driver configured to perform read operations directed to the system volume from the network restore volume and to perform write operations by writing to the system volume. ### Claim 20 (depends on 19) The system of claim 19, wherein the volume filter driver is configured to complete restoring the system volume from the network restore volume by copying disk sectors from the network restore volume to the system volume. ### Claim 21 (depends on 20) The system of claim 20, further comprising, after restoring the system volume, transitioning the disk filter driver to a pass through mode which directs disk I/O read and write requests to the restored system volume. ### Claim 22 (depends on 19) The system of claim 19, wherein the network boot loader is configured to mount the system volume and redirect an interrupt associated with disk I/O to a redirector function configured to perform the read operations directed to the system volume by reading from the network restore volume and to perform the write operations by writing to the system volume. ### Claim 23 (depends on 19) The system of claim 19, wherein the network backup image is stored in a virtual hard disk (VHD). ### Claim 24 (depends on 23) The system of claim 23, wherein the network backup image is exposed to the computing system as a block device. ### Claim 25 A system, comprising: a processor; and a memory storing code, which, when executed on the processor, performs an operation for restoring a system volume on a computing system from a network restore volume, the operation comprising: receiving an indication to restore the system volume from the network restore volume, launching a network boot loader configured to perform disk I/O on the computing system, wherein the network boot loader is configured to mount the network restore volume, and wherein the network restore volume is stored in a parent virtual hard disk (VHD) and differencing VHD, and wherein read operations are performed by reading from the parent VHD and wherein write operations are accumulated in the differencing VHD, and after the boot loader turns over control for disk I/O to an operating system loaded from the network restore volume, launching a volume filter driver configured to restore the system volume by copying blocks from the mounted network restore volume.