High resolution tape directory recovery by writing a null data set
AssigneeInternational Business Machines Corporation
InventorsTsuyoshi Miyamura, Setsuko Masuda, Hironobu Nagura
Life of this patent
Estimating the term…
Abstract
In an approach to HRTD recovery by writing the HRTD in a null data set, responsive to receiving a request to write a data set to a magnetic tape, a lead data set of a current wrap of a plurality of wraps of the magnetic tape is written, wherein the lead data set of the current wrap includes a current wrap HRTD that contains one or more directory records for each wrap of the plurality of wraps from a lead wrap of the plurality of wraps through a first prior wrap of the plurality of wraps, and further wherein the first prior wrap immediately precedes the current wrap.
Claims17
A computer-implemented method for high-resolution tape directory (HRTD) recovery, the computer-implemented method comprising:
- responsive to receiving a request to write a data set to a magnetic tape, writing, by one or more computer processors, a lead data set of a current wrap of a plurality of wraps of the magnetic tape, wherein the lead data set of the current wrap includes a current wrap HRTD that contains one or more directory records for each wrap of the plurality of wraps from a lead wrap of the plurality of wraps through a first prior wrap of the plurality of wraps, and further wherein the first prior wrap immediately precedes the current wrap;
- receiving, by the one or more computer processors, a signal to recover an end of data (EOD) HRTD for an EOD wrap of the plurality of wraps;
- responsive to determining that a first valid HDS exists on the EOD wrap, reading, by the one or more computer processors, the first valid HDS from the EOD wrap;
- recovering, by the one or more computer processors, an EOD wrap HRTD for the EOD wrap;
- and
- appending, by the one or more computer processors, one or more EOD wrap directory records to the EOD wrap HRTD to recover a whole tape HRTD, wherein the one or more EOD wrap directory records are read by scanning the EOD wrap from a beginning of the EOD wrap to a last data set of the EOD wrap.
A computer program product for high-resolution tape directory (HRTD) recovery, the computer program product comprising one or more computer readable storage media and program instructions stored on the one or more computer readable storage media, the program instructions including instructions to:
- responsive to receiving a request to write a data set to a magnetic tape, write a lead data set of a current wrap of a plurality of wraps of the magnetic tape, wherein the lead data set of the current wrap includes a current wrap HRTD that contains one or more directory records for each wrap of the plurality of wraps from a lead wrap of the plurality of wraps through a first prior wrap of the plurality of wraps, and further wherein the first prior wrap immediately precedes the current wrap;
- receiving, by the one or more computer processors, a signal to recover an end of data (EOD) HRTD for an EOD wrap of the plurality of wraps;
- responsive to determining that a first valid HDS exists on the EOD wrap, reading, by the one or more computer processors, the first valid HDS from the EOD wrap;
- recovering, by the one or more computer processors, an EOD wrap HRTD for the EOD wrap;
- and
- appending, by the one or more computer processors, one or more EOD wrap directory records to the EOD wrap HRTD to recover a whole tape HRTD, wherein the one or more EOD wrap directory records are read by scanning the EOD wrap from a beginning of the EOD wrap to a last data set of the EOD wrap.
A computer system for high-resolution tape directory (HRTD) recovery, the computer system comprising:
- one or more computer processors;
- one or more computer readable storage media;
- and
- program instructions stored on the one or more computer readable storage media for execution by at least one of the one or more computer processors, the stored program instructions including instructions to:
- responsive to receiving a request to write a data set to a magnetic tape, write a lead data set of a current wrap of a plurality of wraps of the magnetic tape, wherein the lead data set of the current wrap includes a current wrap HRTD that contains one or more directory records for each wrap of the plurality of wraps from a lead wrap of the plurality of wraps through a first prior wrap of the plurality of wraps, and further wherein the first prior wrap immediately precedes the current wrap;
- receiving, by the one or more computer processors, a signal to recover an end of data (EOD) HRTD for an EOD wrap of the plurality of wraps;
- responsive to determining that a first valid HDS exists on the EOD wrap, reading, by the one or more computer processors, the first valid HDS from the EOD wrap;
- recovering, by the one or more computer processors, an EOD wrap HRTD for the EOD wrap;
- and
- appending, by the one or more computer processors, one or more EOD wrap directory records to the EOD wrap HRTD to recover a whole tape HRTD, wherein the one or more EOD wrap directory records are read by scanning the EOD wrap from a beginning of the EOD wrap to a last data set of the EOD wrap.
Dependencies are inferred from the claim text.