Validating storage virtualization metadata supporting redirection
AssigneeEMC IP Holding Company LLC
InventorsXiangping Chen, Uri Shabi, Ronen Gazit
Life of this patent
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Abstract
A technique for validating metadata includes creating log entries for virtualization structures pointed to by mapping pointers in a mapping tree and processing the log entries in multiple passes. A current pass validates a current level of redirection and creates new log entries to be processed during a next pass. The new log entries represent a next level of redirection, and as many next passes are processed in sequence as there are next levels of redirection.
Claims20
A method of validating storage virtualization metadata, the method comprising:
- while scanning a plurality of mapping pointers in a metadata mapping tree of a storage system, creating a first set of log entries for VLBEs (virtual block elements) pointed to by the plurality of mapping pointers;
- during a first processing pass, (i) validating a set of metadata of the VLBEs of the first set of log entries and (ii) creating a second set of log entries, the second set of log entries created for VLBEs of the first set of log entries which are themselves sources or targets of redirection of other VLBEs of the storage system;
- and
- during a second processing pass, validating one or more metadata elements of the VLBEs of the second set of log entries.
A computerized apparatus, comprising control circuitry that includes a set of processing units coupled to memory, the control circuitry constructed and arranged to:
- while scanning a plurality of mapping pointers in a metadata mapping tree of a storage system, create a first set of log entries for VLBEs (virtual block elements) pointed to by the plurality of mapping pointers;
- during a first processing pass, (i) validate a set of metadata of the VLBEs of the first set of log entries and (ii) create a second set of log entries, the second set of log entries created for VLBEs of the first set of log entries which are themselves sources or targets of redirection of other VLBEs of the storage system;
- and
- during a second processing pass, validate one or more metadata elements of the VLBEs of the second set of log entries.
A computer program product including a set of non-transitory, computer-readable media having instructions which, when executed by control circuitry of a computerized apparatus, cause the computerized apparatus to perform a method of validating storage virtualization metadata, the method comprising:
- while scanning a plurality of mapping pointers in a metadata mapping tree of a storage system, creating a first set of log entries for VLBEs (virtual block elements) pointed to by the plurality of mapping pointers;
- during a first processing pass, (i) validating a set of metadata of the VLBEs of the first set of log entries and (ii) creating a second set of log entries, the second set of log entries created for VLBEs of the first set of log entries which are themselves sources or targets of redirection of other VLBEs of the storage system;
- and
- during a second processing pass, validating one or more metadata elements of the VLBEs of the second set of log entries.
Dependencies are inferred from the claim text.