摘要:
A mechanism is provided for controlling a solid state storage device in which the solid state storage comprises erasable blocks each comprising a plurality of data write locations. Input data is stored in successive groups of data write locations, each group comprising write locations in a set of erasable blocks in each of a plurality of logical subdivisions of the solid state storage. The input data is error correction encoded such that each group contains an error correction code for the input data in that group. Metadata, indicating the location of input data in the solid state storage, is maintained in memory. An indication of validity of data stored in each data write location is also maintained. Prior to erasing a block, valid input data is recovered from the group containing write locations in that block. The recovered data is then re-stored as new input data.
摘要:
In one embodiment, a method of storing data includes storing a first copy of data in a solid state memory and storing a second copy of the data in a hard disk drive memory substantially simultaneously with the storing the first copy. In another embodiment, a system for storing data includes a solid state memory, at least one hard disk drive memory, and a controller for controlling storage of data in the solid state memory and the hard disk drive memory. Other methods, systems, and computer program products are also described according to various embodiments.
摘要:
For efficient track destage in secondary storage in a more effective manner, for temporal bits employed with sequential bits for controlling the timing for destaging the track in a primary storage, the temporal bits and sequential bits are transferred from the primary storage to the secondary storage. The temporal bits are allowed to age on the secondary storage.
摘要:
For movement of partial data segments within a computing storage environment having lower and higher levels of cache by a processor, a whole data segment containing one of the partial data segments is promoted to both the lower and higher levels of cache. Requested data of the whole data segment is split and positioned at a Most Recently Used (MRU) portion of a demotion queue of the higher level of cache. Unrequested data of the whole data segment is split and positioned at a Least Recently Used (LRU) portion of the demotion queue of the higher level of cache. The unrequested data is pinned in place until a write of the whole data segment to the lower level of cache completes.
摘要:
A system, method apparatus, and computer readable medium for managing renewal of a dynamic set of data items. Each data item has an associated renewal deadline, in a data item management system. A renewal schedule allocates to each data item a renewal interval for renewal of the data item. On addition of a new data item, if a potential renewal interval having a duration required for renewal of the data item, and having an ending at the renewal deadline for that item does not overlap a time period in the schedule during which the system is busy, the renewal schedule is automatically updated by allocating the potential renewal interval to the new data item. If the potential renewal interval does overlap a busy period, the renewal schedule is automatically updated by selecting an earlier renewal interval for at least one data item in the set.
摘要:
A method for garbage collection in a solid state drive (SSD) includes determining whether the SSD is idle by a garbage collection module of the SSD; based on determining that the SSD is idle, determining a victim block from a plurality of memory blocks of the SSD; determining a number of valid pages in the victim block; comparing the determined number of valid pages in the victim block to a valid page threshold; and based on the number of valid pages in the victim block being less than the valid page threshold, issuing a garbage collection request for the victim block.
摘要:
The population of data to be admitted into secondary data storage cache of a data storage system is controlled by determining heat metrics of data of the data storage system. If candidate data is submitted for admission into the secondary cache, data is selected to tentatively be evicted from the secondary cache; candidate data provided to the secondary data storage cache is rejected if its heat metric is less than the heat metric of the tentatively evicted data; and candidate data submitted for admission to the secondary data storage cache is admitted if its heat metric is equal to or greater than the heat metric of the tentatively evicted data.
摘要:
Methods and systems for reading from and writing to a distributed, asynchronous and fault-tolerant storage system. The storage system includes storage nodes communicating with clients. The method includes a first client writing an object to the storage system and a second client reading the object from the storage system. For the first client, previous transient metadata relating to a previously written version of the object is retrieved and a new version of the object together with new transient metadata is stored. For the second client, a set of transient metadata from a third set of nodes amongst storage nodes is retrieved, a specific version of the object as stored on the storage system is determined, and a specific version of the corresponding object from a fourth set of nodes amongst storage nodes is retrieved. Two sets of nodes amongst all sets have at least one node in common.
摘要:
Exemplary embodiments include a method for reducing access contention in a flash-based memory system, the method including selecting a chip stripe in a free state, from a memory device having a plurality of channels and a plurality of memory blocks, wherein the chip stripe includes a plurality of pages, setting the ship stripe to a write state, setting a write queue head in each of the plurality of channels, for each of the plurality of channels in the flash stripe, setting a write queue head to a first free page in a chip belonging to the channel from the chip stripe, allocating write requests according to a write allocation scheduler among the channels, generating a page write and in response to the page write, incrementing the write queue head, and setting the chip stripe into an on-line state when it is full.
摘要:
Methods and systems for reading from and writing to a distributed, asynchronous and fault-tolerant storage system. The storage system includes storage nodes communicating with clients. The method includes a first client writing an object to the storage system and a second client reading the object from the storage system. For the first client, previous transient metadata relating to a previously written version of the object is retrieved and a new version of the object together with new transient metadata is stored. For the second client, a set of transient metadata from a third set of nodes amongst storage nodes is retrieved, a specific version of the object as stored on the storage system is determined, and a specific version of the corresponding object from a fourth set of nodes amongst storage nodes is retrieved. Two sets of nodes amongst all sets have at least one node in common.