Abstract: A storage array uses paged metadata. Each storage director has access to a plurality of object storage systems which describe locations of paged metadata in backing storage. Each object storage system includes different types of inodes which describe objects in backing storage. The object storage systems are used to locate and relocate metadata for loading into global memory, and creation and deletion of objects. An object storage system may be selected based on factors including ratio of different inode types, locality of object usage and anticipated object activity level.

Abstract: A storage array uses paged metadata. Each storage director has access to a plurality of object storage subsystems in a global memory. The object storage subsystems describe locations of paged metadata in backing storage. Each object storage subsystem includes a unique identifier, a pointer to a descriptive data structure that indicates availability of free space for paged metadata for that object storage subsystem, and different types of inodes which describe objects in backing storage. The object storage subsystems are used to locate metadata for loading into global memory, and creation and deletion of objects.

Abstract: A storage array uses paged metadata. Each storage director has access to a plurality of object storage systems which describe locations of paged metadata in backing storage. Each object storage system includes different types of inodes which describe objects in backing storage. The object storage systems are used to locate and relocate metadata for loading into global memory, and creation and deletion of objects. An object storage system may be selected based on factors including ratio of different inode types, locality of object usage and anticipated object activity level.

Abstract: A storage array uses paged metadata. Each storage director has access to a plurality of object storage systems which describe locations of paged metadata in backing storage. Each object storage system includes different types of inodes which describe objects in backing storage. The object storage systems are used to locate and relocate metadata for loading into global memory, and creation and deletion of objects. An object storage system may be selected based on factors including ratio of different inode types, locality of object usage and anticipated object activity level.

Abstract: Described are techniques for determining a cache slot. A set of criteria for each of a plurality of families is received. A received data operation associated with a first of said plurality of families is obtained. It is determined, in accordance with the criteria associated with the received data operation, whether to allocate a cache slot in the cache for the received data operation. The criteria for the first family includes a minimum value and a maximum value used in determining a cache partition size range for the first family. The maximum value is used in determining a maximum cache partition size allowable for the first family.

Abstract: Software behavior is analyzed. A disk drive controller has a processor executing computer software stored in a memory communicating with the processor via a local bus. In the controller, computer executable program code is identified that includes a set of computer executable program instructions for recording analytical data for at least a subset of the computer executable program code. The set of computer executable program instructions is disabled from executing. Without halting execution of the computer executable program code, execution of the set of computer executable program instructions is enabled.

Abstract: A method of providing synchronized operational information for a host computer and an attached storage system is provided. The method includes providing a trace buffer in a memory of the storage system. A special command is created which allows a host computer to write information to the provided trace buffer. The special command uses a command from the communication protocol command set is a specific way in order to effectuate the trace buffer entry. The trace buffer entry will have a time component based on the storage system time clock. Thus, host activity may be synchronized in time with the storage system activity. In addition to the trace buffer, a statistics table is provided which maintains a log of which applications programs running on specific hosts, accessed the devices of the storage system.

Abstract: An impedance measurement system for electrocardiographic recorders which allows measurement of the electrode channel impedance without the need for a separate piece of equipment. The impedance measurement system, which is an integral part of the recorder, applies complementary oscillating currents having short transition times to an electrode channel defined by a pair of electrode leads, a pair of electrodes and the patient tissues. The analog current signals flowing through the electrode channel create a voltage across the electrode channel which is amplified and applied to a dual range filtering stage. The low range section of the dual range filtering stage generates a time-dependent signal which causes the output of the low range filtering circuit to produce a signal applied to the timing input of a microprocessor. The microprocessor calculates the time elapsed between each transition of the oscillating current signals and the occurrence of a signal at the output of the low range filtering circuitry.

Abstract: A method and apparatus for digitally storing episodic signals, such as, electrocardiogram signals is disclosed. In a preferred embodiment, the apparatus includes, for each signal channel, an input amplifier, an analog-to-digital converter, and a double data buffer. The incoming signal on each channel is converted to a multibit digital number a fixed sampling rate. Each multibit digital number is stored in a location in the double data buffer. When a fixed amount of data is stored in the buffer, a processor examines the data to determine the periods during which the signal is undergoing the most rapid rate of change. For these periods, both an indicator of the period, and a first number of data samples per unit time is stored in a bulk solid state memory. Preferably, the data stored is a number relating to the difference between the value of the sample and a number related to the value of the last sample.