Locking allocated data space

摘要

Locking allocated data space is disclosed. An indication is received that certain previous version data is required to be retained. A map of metadata records, each associated with a journaling process write of previous version data which write includes previous version data required to be retained beyond the protection window, is built. In some embodiments, the map associates a write time with each record in the map. A reclamation process checks to determine whether any storage proposed to be reclaimed is included in the map of record identifiers. In some embodiments, the determination is made based at least in part on the write time associated in the map with at least a first record identifier in time sorted order.

主权项

1. A method of locking allocated data space, comprising:
providing continuous data protection for a protected entity over a window of continuous data protection, where the protected entity as it was at any state during the window of continuous data protection is able to be accessed if desired with write-by-write granularity, including by:
having a journaling process write to allocated data space previous version data comprising copies of writes to the protected entity; andgenerating one or more metadata records corresponding to the copies of the writes stored in the allocated data space; receiving, at a processor, an indication that selected previous version data associated with one or more selected copies of writes stored in the allocated data space are required to be retained; using the processor to store in a locked list, for each of those one or more metadata records corresponding to the one or more selected copies of writes, an identifier that identifies the metadata record as one associated with a copy of a write that is to be retained; and determining whether some allocated data space under consideration is available for reclamation based at least in part on (1) whether there is a stored identifier in the locked list and (2) the window of continuous data protection, wherein it is determined to not reclaim for reuse any storage location associated with a metadata record for which the corresponding identifier has been stored in the locked list.