Method and system for transparent restore of junction file types

A method of backing up redirection identifier file type information in a backup and restore operation comprising:

• performing a backup operation in a clustered storage system having a plurality of storage devices by scanning each storage device and inspecting at least one inode including a file type field on each storage device;
• obtaining, in response to encountering a redirection identifier file type in said inode during scanning of each storage device, an inode number and a generation number;
• indexing into a junction table entry of a junction table utilizing the inode number and the generation number to retrieve redirection identifier information indicating that data is stored at a storage location different from a storage location where the data was originally sought;
• and
• encoding, in response to obtaining said redirection identifier information, said redirection identifier information as a symbolic link and recording said symbolic link in a back up storage medium.

A storage system including a backup and restore program, comprising:

• redirection identifier information embedded within a symlink directive indicating that data is stored at a storage location different from a storage location where the data was originally sought;
• one or more processors to store a backup of the storage system to a tape by scanning storage elements of the storage system to be backed up to the tape, where a redirection identifier file type is detected during the scan to obtain an inode number and generation number to retrieve the redirection identifier information from a junction table entry of a junction table, wherein the backup comprises backup data and said redirection identifier information embedded within the symlink directive;
• and
• the one or more processors to restore the backup of the storage system.

A non-transitory computer readable storage medium containing executable program instructions executed by a processor, comprising:

• program instructions that perform a backup operation in a clustered storage system having a plurality of storage devices by scanning each storage device and inspecting at least one inode including a file type field on each storage device;
• program instructions that encounter a redirection identifier file type in said inode during the scanning, wherein said redirection identifier file type indicates that the data is stored at a storage location different from a storage location where the data was originally sought;
• program instructions that obtain an inode number and a generation number in response to encountering said redirection identifier file type in said inode;
• program instructions that index into a junction table utilizing the inode number and the generation number to retrieve redirection identifier information associated with the encountered redirection identifier file type;
• program instructions that encode said redirection identifier information as a symbolic link and embedding said symbolic link in a sequential image stream;
• and
• program instructions that write an encoded sequential image stream comprising backup data and said redirection identifier information to a backup storage medium.

A method, comprising:

• performing a backup operation in a clustered storage system having a plurality of storage devices by scanning each storage device and inspecting at least one inode including a file type field on each storage device;
• encountering a junction file type in said inode during the scanning of each storage device in performing the backup operation, wherein said junction file type indicates that data is not stored at a storage location originally used to reference the data but is stored at some other storage location;
• in response to encountering said junction file type in said inode during the scanning, obtaining an inode number and a generation number;
• utilizing the inode number and the generation number to extract junction information from a junction table;
• encoding said junction information as a symbolic link and embedding said symbolic link in a sequential image stream;
• and
• writing an encoded sequential image stream comprising backup data and said junction information to a backup storage medium.