Method and system for accessing virtual machine state while virtual machine restoration is underway
AssigneeEMC IP Holding Company LLC
InventorsAaditya Bansal, Shelesh Chopra, Soumen Acharya, Sunil Yadav
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Abstract
An optimized solution for accessing virtual machine state while restoration of a respective virtual machine is underway. Specifically, the optimized solution disclosed herein implements a fetching mechanism for retrieving granular virtual machine state over a network and/or from a remote storage system. The fetching mechanism leverages block allocation information in parallel with disk caching to provide instant (or near instant) access to a virtual machine state while also, concurrently, restoring the respective virtual machine.
Claims20
A method for retrieving data, comprising:
- receiving, from a granular virtual machine (GVM), a first read request comprising a first filename;
- mapping the first filename to a first sector number;
- deriving a first data block number using the first sector number;
- hashing the first data block number to obtain a first block number digest (BND);
- performing a first lookup on a disk cache using the first BND;
- making a first determination, based on the first lookup, that the disk cache lacks the first BND;
- based on the first determination and through a first parallel thread:
- obtaining, from a first replica virtual machine disk and through a symbolic link, first sector data stored at a first disk sector associated with the first sector number;
- and
- providing, in response to the first read request, the first sector data to the GVM.
A system, comprising:
- a first replica virtual machine disk;
- a disk cache;
- a granular virtual machine (GVM) executing on a first computer processor;
- and
- a first virtual machine backup intelligence (VMBI) executing on the first computer processor and operatively connected to the GVM, the disk cache, and the first replica virtual machine disk,
- wherein the first VMBI is programmed to:
- receive, from the GVM, a first read request comprising a first filename;
- map the first filename to a first sector number;
- derive a first data block number using the first sector number;
- hash the first data block number to obtain a first block number digest (BND);
- perform a first lookup on the disk cache using the first BND;
- make a first determination, based on the first lookup, that the disk cache lacks the first BND;
- based on the first determination and through a first parallel thread:
- obtain, from the first replica virtual machine disk and through a symbolic link, first sector data stored at a first disk sector associated with the first sector number;
- and
- provide, in response to the first read request, the first sector data to the GVM.
A non-transitory computer readable medium (CRM) comprising computer readable program code, which when executed by a computer processor, enables the computer processor to:
- receive, from a granular virtual machine (GVM), a first read request comprising a first filename;
- map the first filename to a first sector number;
- derive a first data block number from the first sector number;
- hash the first data block number to obtain a first block number digest (BND);
- perform a first lookup on a disk cache using the first BND;
- make a first determination, based on the first lookup, that the disk cache lacks the first BND;
- based on the first determination and through a first parallel thread:
- obtain, from a first replica virtual machine disk and through a symbolic link, first sector data stored at a first disk sector associated with the first sector number;
- and
- provide, in response to the first read request, the first sector data to the GVM.
Dependencies are inferred from the claim text.