摘要:
Methods and apparatuses that maintain an access history of a file allocated with allocation blocks in storage devices are described. In response to receiving a usage request to allocate additional space for the file, an allocation block size may be adjusted or adapted based on the access history. The storage devices may be allocated with one or more allocation blocks using the adapted allocation block size to provide requested space for the file.
摘要:
Methods and apparatuses that maintain an access history of a file allocated with allocation blocks in storage devices are described. In response to receiving a usage request to allocate additional space for the file, an allocation block size may be adjusted or adapted based on the access history. The storage devices may be allocated with one or more allocation blocks using the adapted allocation block size to provide requested space for the file.
摘要:
Methods and apparatuses that search tree representations of a bitmap for available blocks to allocate in storage devices are described. An allocation request for a file may be received to initiate the search. In one embodiment, the bitmap may include an array of bits corresponding to blocks in the storage devices. Each bit may indicate whether one of the blocks is available. The tree representations may include at least one red-black tree having nodes corresponding to one or more consecutive bits in the bitmap indicating an extent of available blocks. One of the tree representations may be selected according to a file associated with an allocation request to identify an extent of available block matching the allocation request. The tree representations may be synchronized as the bitmap is updated with changes of block allocations in the storage devices.
摘要:
Methods and apparatuses that maintain birth time for a file system to optimize file update operations are described. The file system can include a plurality of snapshots or clones of data stored in one or more extents of blocks allocated in a storage device. Each extent may be associated with a time stamp according to the birth time. A request may be received from an executable using the file system to update data in a particular extent associated with a particular time stamp. In response, the current birth time in the file system and the particular time stamp may be compared to determine if the particular extent is not shared by more than one of the snapshots. If the particular time stamp is equal to the current birth time, the particular extent may be updated directly without performing an expensive operation to check whether a reference count of the particular extent is equal to one.
摘要:
Methods and apparatuses that search tree representations of a bitmap for available blocks to allocate in storage devices are described. An allocation request for a file may be received to initiate the search. In one embodiment, the bitmap may include an array of bits corresponding to blocks in the storage devices. Each bit may indicate whether one of the blocks is available. The tree representations may include at least one red-black tree having nodes corresponding to one or more consecutive bits in the bitmap indicating an extent of available blocks. One of the tree representations may be selected according to a file associated with an allocation request to identify an extent of available block matching the allocation request. The tree representations may be synchronized as the bitmap is updated with changes of block allocations in the storage devices.
摘要:
Methods and apparatuses that maintain birth time for a file system to optimize file update operations are described. The file system can include a plurality of snapshots or clones of data stored in one or more extents of blocks allocated in a storage device. Each extent may be associated with a time stamp according to the birth time. A request may be received from an executable using the file system to update data in a particular extent associated with a particular time stamp. In response, the current birth time in the file system and the particular time stamp may be compared to determine if the particular extent is not shared by more than one of the snapshots. If the particular time stamp is equal to the current birth time, the particular extent may be updated directly without performing an expensive operation to check whether a reference count of the particular extent is equal to one.