Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first target volume and a second target volume. The method detects a corruption of the first source volume and, if a first restoration of the first source volume from the first target volume is in progress, creates a third target volume from the second target volume and directs I/O operations for the first source volume to the third target volume. The first source volume is then restored from the third target volume.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first target volume and a second target volume. The method detects a corruption of the first source volume and, if a first restoration of the first source volume from the first target volume is in progress, creates a third target volume from the second target volume and directs I/O operations for the first source volume to the third target volume. The first source volume is then restored from the third target volume.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first target volume and a second target volume. The method detects a corruption of the first source volume and, if a first restoration of the first source volume from the first target volume is in progress, creates a third target volume from the second target volume and directs I/O operations for the first source volume to the third target volume. The first source volume is then restored from the third target volume.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first target volume and a second target volume. The method detects a corruption of the first source volume and, if a first restoration of the first source volume from the first target volume is in progress, creates a third target volume from the second target volume and directs I/O operations for the first source volume to the third target volume. The first source volume is then restored from the third target volume.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first clone point-in-time target volume, and a second point-in-time target volume that is a point-in-time copy of the first point-in-time target volume. Grain background copies from the first source volume to the first clone point-in-time target volume are tracked, and, if the first clone point-in-time target volume is corrupted, a third point-in-time target volume is created from the second point-in-time target volume. I/O for the first clone point-in-time target volume is directed to the third point-in-time target volume. The first clone point-in-time target volume is cleaned to the second point-in-time target volume. The first clone point-in-time target volume is restarted from the third point-in-time target volume and each grain of the first clone point-in-time target volume that has not been background copied is copied from the cascade to the first clone point-in-time target volume.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first target volume and a second target volume. The method detects a corruption of the first source volume and, if a first restoration of the first source volume from the first target volume is in progress, creates a third target volume from the second target volume and directs I/O operations for the first source volume to the third target volume. The first restoration is stopped. The first source volume is restored from the third target volume, and the third target volume is deleted.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first clone point-in-time target volume, and a second point-in-time target volume that is a point-in-time copy of the first point-in-time target volume. Grain background copies from the first source volume to the first clone point-in-time target volume are tracked, and, if the first clone point-in-time target volume is corrupted, a third point-in-time target volume is created from the second point-in-time target volume. I/O for the first clone point-in-time target volume is directed to the third point-in-time target volume. The first clone point-in-time target volume is cleaned to the second point-in-time target volume. The first clone point-in-time target volume is restarted from the third point-in-time target volume and each grain of the first clone point-in-time target volume that has not been background copied is copied from the cascade to the first clone point-in-time target volume.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first target volume and a second target volume. The method detects a corruption of the first source volume and, if a first restoration of the first source volume from the first target volume is in progress, creates a third target volume from the second target volume and directs I/O operations for the first source volume to the third target volume. The first restoration is stopped. The first source volume is restored from the third target volume, and the third target volume is deleted.

Abstract: A data receiver module receives, at a storage device simulator, a data transmission from a storage controller being tested. The data transmission includes data and metadata. The metadata is associated with the data. A signature receiver module receives a signature from the storage controller as part of the data transmission. The signature is used to distinguish the metadata from the data. A data/metadata determination module examines the data transmission and determines data from metadata using the signature. A metadata storage module stores the metadata of the data transmission on the storage device simulator in response to the data transmission including metadata. The data storage simulator includes a data storage device. A data discard module discards the data of the data transmission in response to the data transmission including data.

Abstract: A data receiver module receives, at a storage device simulator, a data transmission from a storage controller being tested. The data transmission includes data and metadata. The metadata is associated with the data. A signature receiver module receives a signature from the storage controller as part of the data transmission. The signature is used to distinguish the metadata from the data. A data/metadata determination module examines the data transmission and determines data from metadata using the signature. A metadata storage module stores the metadata of the data transmission on the storage device simulator in response to the data transmission including metadata. The data storage simulator includes a data storage device. A data discard module discards the data of the data transmission in response to the data transmission including data.

Abstract: A line interlaced video signal having odd and even alternating fields produces an alphanumeric character display in the form of a dot matrix character, each matrix location comprising segments of two next adjacent lines in the display. To improve the resolution of the characters, diagonals are detected and partly filled to provide a rounded effect. Two parallel-in serial-out shift registers are used, one of the shift registers having an associated input buffer store. A binary word representing dot information for one row of a character is read out from a dot matrix character generator ROM and loaded into one of the shift registers. On even (odd) fields the ROM output for the previous (succeeding) row is read and loaded into the other shift register. The last two bits of the two shift registers are compared to detect diagonals in the character information and used to modify the video signal to lengthen the leading or trailing edge of the corresponding dot to produce the rounded character.