Managing cache backup and restore for continuous data replication and protection
AssigneeLenovoemc Limited
InventorsVamsikrishna Sadhu, Brian R. Gruttadauria, Suresh Kumar Kalidindi
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Abstract
A method is used for managing cache backup and restore for continuous data replication and protection. I/O operations are quiesced at a cache module. A first snapshot of a storage object and a second snapshot of an SSD cache object are taken. The I/O operations at the cache module are unquiesced. A single backup image comprising the first snapshot and the second snapshot is created. The single backup image is sent to a first data protection appliance (DPA) and recorded in a journal.
Claims20
A method, comprising:
- quiescing I/O operations at a cache;
- taking a first snapshot of a storage object and a second snapshot of a cache object;
- unquiescing I/O operations at the cache;
- creating, at least one backup image comprising the first snapshot and the second snapshot;
- and
- storing the backup image;
- wherein creating the backup image comprises:
- calculating a backup image size;
- writing, to the backup image, a backup storage object data blocks from the storage object;
- updating the backup header with storage object metadata and cache object metadata;
- writing the backup header to the backup image;
- reading, from the cache object, cache superblock and dirty region logging (DRL) metadata and reading, from the cache object, cache data blocks determined to have a DRL state that is dirty;
- and
- writing, to the backup image, the cache superblock and dirty region logging (DRL) metadata and the cache data blocks determined to have a DRL state that is dirty.
A system, comprising:
- a processor;
- and
- storage accessible to the processor and bearing instructions executable by the processor to:
- quiesce I/O operations at a cache;
- take a first snapshot of at least a portion of data in storage and a second snapshot of at least a portion of data in the cache;
- unquiesce I/O operations at the cache;
- create, within a threshold time of unquiescing I/O operations at the cache, at least one backup image comprising the first snapshot and the second snapshot;
- and
- store the backup image;
- wherein creation of the backup image comprises:
- writing, to the backup image, a backup of at least one storage data block from the storage;
- including, in a backup header, storage metadata;
- writing, to the backup image, the backup header;
- reading, from the cache, at least one cache data block determined to have a dirty region logging (DRL) start that is dirty;
- and
- writing, to the backup image, the at least one cache data block determined to have a DRL state that is dirty.
A computer readable storage medium that is not a transitory signal, the computer readable storage medium comprising instructions executable by a processor to:
- quiesce I/O operations at a cache;
- take a first snapshot of at least a portion of a storage area and a second snapshot of at least a portion of the cache;
- unquiesce I/O operations at the cache;
- create, within a threshold time of unquiescing I/O operations at the cache, at least one backup image comprising the first snapshot and the second snapshot;
- and
- store the backup image;
- wherein creation of the backup image comprises:
- writing, to the backup image, a backup of at least one storage data block from the storage area;
- including, in a backup header, storage area metadata;
- writing, in the backup image, the backup header;
- reading, from the cache, at least one cache data block determined to have a dirty region logging (DRL) state that is dirty;
- and
- writing, to the backup image, the at least one cache data block determined to have a DRL state that is dirty.
Dependencies are inferred from the claim text.