Abstract: Aspects for increasing concurrency during staging and destaging of a log structured array (LSA) are described. In an exemplary method aspect, the method includes determining a process type making a request for access to a locking mechanism associated with an LSA directory entry for a logical track, and determining a lock status for the locking mechanism. Access to the locking mechanism is then provided according to the determined process type and lock status. Further, a destaging process is allowed to obtain an available locking mechanism in a read-write mode, a staging process is allowed to obtain an available locking mechanism in a read-only mode, and a garbage collection process is allowed to obtain an available locking mechanism initially in a read-only mode and subsequently in a read-write mode, wherein increased concurrency results during the staging and destaging processes.

Abstract: A food container includes a container box, and a box cover. An annular locking flange formed on the box cover is snapped on the snapping flange formed on the container box. An L-shaped catch ring is located under the snapping flange, and a press plate is extended from the catch ring. A breakable line is connected between the press plate and the catch ring. A plurality of thin posts that are easily broken and removed are connected between the press plate and the wall of the container box. When the press plate is subjected to a pressing force, the press plate is broken to form an opening, thereby facilitating the press plate being bent upward through the opening to urge the bottom of the box cover, such that the box cover can be removed from the container box, thereby opening the food container.

Abstract: In a storage system comprising an array of storage devices, including a processor and memory, a plurality of logical tracks are organized on the storage devices in segments comprising columns striped across the storage devices. A system and method are provided for storing logical tracks in the storage devices. Sequentially logically related logical tracks are stored together in neighborhoods. Logical tracks of the same neighborhood destaged at the same time are assigned to a single open segment with other logical tracks of the same neighborhood type. The time at which open segments are designated as closed segments to be written to the storage devices is based on performance, disk utilization and memory utilization criteria. Logical tracks are never split between segment columns. Also, attempts are made not to split a neighborhood of logical tracks being destaged together between segment columns.

Abstract: Aspects for preventing deadlock in a log structured array are described. In an exemplary method aspect, and system for providing same, the method includes monitoring available segments to determine when to reserve an open segment, identifying a process type requesting access to the open segment, and limiting access to one process type for the reserved segment. Limiting access further includes limiting access to a garbage collection process.

Abstract: In a storage system comprising an array of storage devices, including a processor and memory, a plurality of logical tracks are organized on the storage devices in segments comprising columns striped across the storage devices. A system and method are provided for storing logical tracks in the storage devices. Sequentially logically related logical tracks are stored together in neighborhoods. Logical tracks of the same neighborhood A0 destaged at the same time are assigned to a single open segment with other logical tracks of the same neighborhood type. The time at which open segments are designated as closed segments to be written to the storage devices is based on performance, disk utilization and memory utilization criteria. Logical tracks are never split between segment columns. Also, attempts are made not to split a neighborhood of logical tracks being destaged together between segment columns.

Abstract: In a storage system comprising an array of storage devices including a processor and memory, a plurality of data blocks are organized on the storage devices in segments striped across the storage devices. A main directory, stored in memory, contains the location on the storage device of each of the data blocks. For each segment a segment directory having information on the data blocks in the segment is stored on the storage devices. When a damaged segment directory is detected, a checkpoint of the main directory is written to the storage devices. A list is maintained of damaged segment directories such that segments on the damaged segment directories list are not garbage collected. Following a main directory recovery procedure, the damaged segment directories are reconstructed using the main directory.

Abstract: In a storage system comprising an array of storage devices including a processor and memory, a plurality of data blocks are organized on the storage devices in segments striped across the storage devices. A main directory stored in memory contains the location on the storage device of each of the current data blocks. A method is provided for recovering a main directory in the event that the main directory becomes damaged. A segment directory having information on the data blocks in the segment is stored as part of the segment on the storage devices. Periodically a checkpoint of the main directory is written to the storage devices. A list is maintained of closed segments written to the storage devices since the checkpoint directory was written to the storage devices.