摘要:
A disk subsystem assures the sequence and the coherence of data updating with two or more disk subsystems is provided with an asynchronous remote copy function. A main center 9 includes a computer system having the configuration of slave subsystems 3-2 to 3-n connected with a master disk subsystem 3-1. It secures the coherence between data at the main center 9 and the remote center 10 at the temporary suspension by repeating temporary suspension and release of the temporary suspension of the remote copy by the master subsystem 3-1 at predetermined opportunities. It also repeats temporary suspension and release of the temporary suspension of the remote copy by slave subsystems 3-2 to 3-n connected to it.
摘要:
A data storage system comprises a magnetic disk, an optical disk, optical disk drive units, and optical disk transport devices for transporting the optical disk to the optical disk drive units as required. The data storage system further comprises a host system for receiving and transmitting a command and data in the format of the magnetic disk and a converter for converting the command and the data between the format of the magnetic disk and that of the optical disk. The optical disk, the optical disk drive unit and the optical disk transport device are controlled by a command and data in the format of the magnetic disk of the host system.
摘要:
A buffer memory capable of storing contents of a plurality of tracks of a disk volume is provided in a disk controller or a disk drive, and in dump processing requested by a higher rank unit (CPU) to the disk controller, the data is immediately transferred from the buffer memory if the data to be dumped is present in the buffer memory, and if the data to be dumped is not present in the buffer memory, dump prefetching into the buffer memory is started and the execution of the dump processing is interrupted so that an on-line input/output operation other than the dump processing is accepted. When the dump prefetching into the buffer memory is over, the interrupted dump processing is resumed.
摘要:
An external storage system connected to a host apparatus includes a plurality of storage devices, and a control unit for controlling the above described plurality of storage devices, wherein the above described control unit manages a storage space formed by the above described plurality of storage devices by dividing the storage space into a first storage pool to be directly accessed by the above described host apparatus and a second storage pool not to be directly accessed by the above described host apparatus.
摘要:
A disk subsystem assures the sequence and the coherence of data updating with two or more disk subsystems is provided with an asynchronous remote copy function. A main center 9 includes a computer system having the configuration of slave subsystems 3-2 to 3-n connected with a master disk subsystem 3-1. It secures the coherence between data at the main center 9 and the remote center 10 at the temporary suspension by repeating temporary suspension and release of the temporary suspension of the remote copy by the master subsystem 3-1 at predetermined opportunities. It also repeats temporary suspension and release of the temporary suspension of the remote copy by slave subsystems 3-2 to 3-n connected to it.
摘要:
Two data centers located in the vicinity are connected using a synchronous transfer copy function, and one of the data centers is coupled with a third data center disposed at a remote location by an asynchronous remote copying function. The order whereat a storage sub-system located in the vicinity has received data from a host is consistently guaranteed, and the third data center holds the data. Further, each storage sub-system includes a function whereby, during normal operation, data can be exchanged and the data update state can be obtained by the storage sub-systems located in the two data centers that do not directly engage in data transmission.
摘要:
A disk subsystem assures the sequence and the coherence of data updating with two or more disk subsystems is provided with an asynchronous remote copy function. A main center 9 includes a computer system having the configuration of slave subsystems 3-2 to 3-n connected with a master disk subsystem 3-1. It secures the coherence between data at the main center 9 and the remote center 10 at the temporary suspension by repeating temporary suspension and release of the temporary suspension of the remote copy by the master subsystem 3-1 at predetermined opportunities. It also repeats temporary suspension and release of the temporary suspension of the remote copy by slave subsystems 3-2 to 3-n connected to it.
摘要:
A buffer memory capable of storing contents of a plurality of tracks of a disk volume is provided in a disk controller or a disk drive, and in dump processing requested by a higher rank unit (CPU) to the disk controller, the data is immediately transferred from the buffer memory if the data to be dumped is present in the buffer memory, and if the data to be dumped is not present in the buffer memory, dump prefetching into the buffer memory is started and the execution of the dump processing is interrupted so that an on-line input/output operation other than the dump processing is accepted. When the dump prefetching into the buffer memory is over, the interrupted dump processing is resumed.
摘要:
In a control unit having a external storage device, a method for selecting a loading method of data stored in the cache memory into the cache memory in accordance with an access pattern to the data, and an apparatus therefor are disclosed. The selection of the loading method is selection of control mode or procedure in accordance with the loading method, and it is attained by a learn function.
摘要:
In a data processing system having a first external memory, a second external memory, and a control memory for storing information on data renewals in the first external memory, a system and a method provide for back-up operations in parallel with ordinary data processing, including dump processing in which renewed data parts in the first external memory are copied as backup data into the second external memory with reference to the contents of the control memory. The method provides the step of storing into the control memory first identifier information for identifying areas of the first external memory where data items were renewed; the step of storing into the control memory second identifier information for identifying areas of the first external memory where data items were renewed during the dump processing; and the step of erasing at completion of the dump processing the first identifier information items except those which identify the same areas as identified by the second identifier information items. Thus, ordinary job processing and the renewals of the data items of the first external memory can be performed even in the course of the data dumping processing.