International Business Machines Corporation

Takeshi Sohda

Norie Iwasaki

Koichi Masuda

Takahiro Tsuda

Tomokazu Nakamura

Tadaaki Minoura

David Michael Morton

Laura Jean Ostasiewski

Yun Mou

Various embodiments are provided for saving a log data in a hierarchical storage management system using a disk system as a primary cache with a tape library as a secondary cache. The user data is stored in the primary cache and written into the secondary cache at a subsequent period of time. Blank tapes in the secondary cache are prepared for storing the user data and the log data, based on priorities. At least one of the blank tapes is selected for copying the log data and the user data from the primary cache to the secondary cache based on priorities.

Saving log data using a disk system as primary cache and a tape library as secondary cache

Various embodiments are provided for saving a log data in a hierarchical storage management system using a disk system as a primary cache with a tape library as a secondary cache. The user data is stored in the primary cache and written into the secondary cache at a subsequent period of time. Blank tapes in the secondary cache are prepared for storing the user data and the log data, based on priorities. At least one of the blank tapes is selected for copying the log data and the user data from the primary cache to the secondary cache based on priorities. The log data is stored in the primary cache.

Various embodiments are provided for saving a log data in a hierarchical storage management system using a disk system as a primary cache with a tape library as a secondary cache. The user data is stored in the primary cache and written into the secondary cache at a subsequent period of time. Blank tapes in the secondary cache is prepared for storing the user data and the log data based on priorities. At least one of the blank tapes is selected for copying the log data and the user data from the primary cache to the secondary cache based on priorities. The log data is stored in the primary cache. The selection of at least one of the blank tapes completely filled with the log data is delayed for writing additional amounts of the user data.

Various embodiments are provided for saving a plurality of log data in a hierarchical storage management system using a disk system as a primary cache with a tape library as a secondary cache. The user data is stored in the primary cache and written into the secondary cache at a subsequent period of time. The plurality of blank tapes in the secondary cache is prepared for storing the user data and the plurality of log data based on priorities. At least one of the plurality of blank tapes is selected for copying the plurality of log data and the user data from the primary cache to the secondary cache based on priorities. The plurality of log data is stored in the primary cache. The selection of at least one of the plurality of blank tapes completely filled with the plurality of log data is delayed for writing additional amounts of the user data.

A copy export application implemented in a computational device receives a request to perform a copy export operation of data and metadata to a selected tape in a tape library coupled to the computational device. The copy export application copies the data from the computational device to the selected tape. The copy export application determines a medium error on the selected tape while copying the metadata from the computational device to the selected tape, subsequent to completion of the copying of the data from the computational device to the selected tape. The copy export application sends a request to a tape control application to replace the selected tape by a new tape and copy the data from the selected tape to the new tape. The copy export application copies the metadata to the new tape.

Recovery from medium error on tape on which data and metadata are to be stored by using medium to medium data copy

Various embodiments save a plurality of log data in a hierarchical storage management system using a disk system as a primary cache with a tape library as a secondary cache. The user data is stored in the primary cache and written into the secondary cache at a subsequent period of time. The plurality of blank tapes in the secondary cache is prepared for storing the user data and the plurality of log data based on priorities. At least one of the plurality of blank tapes is selected for copying the plurality of log data and the user data from the primary cache to the secondary cache based on priorities. The plurality of log data is stored in the primary cache. The selection of at least one of the plurality of blank tapes completely filled with the plurality of log data is delayed for writing additional amounts of user data.

A copy export application emented in a computational device receives a request to perform a copy export operation of data and metadata to a selected tape in a tape library coupled to the computational device. The copy export application copies the data from the computational device to the selected tape. The copy export application determines a medium error on the selected tape while copying the metadata from the computational device to the selected tape, subsequent to completion of the copying of the data from the computational device to the selected tape. The copy export application sends a request to a tape control application to replace the selected tape by a new tape and copy the data from the selected tape to the new tape. The copy export application copies the metadata to the new tape.

The present invention is a computer system for performing processing synchronously with an internal system clock. The system includes a time information inputting part for detecting a signal for time notice sent from an external reference clock and acquiring an internal time at the present time from the system clock. The system further includes a time correction controlling part for comparing the time information together with the signal for time notice and the internal time at the time of detecting the signal for time notice and correcting the time of the system clock based on the comparison result. Further, the time correction controlling part calculates a signal interval that is a time difference in said system clock between two consecutive signals for time notice based on the internal time acquired from the time information inputting part, evaluating the calculated signal interval and judging whether or not it is required to correct the internal time.

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Sagamihara, Japan

Takeshi Sohda