Volume coherency verification for sequential-access storage media

A computer program product to enable an application to determine if logical objects on a volume are coherent with the last time the application wrote to the volume, the computer program product comprising a computer-readable storage medium having computer-usable program code embodied therein, the computer-usable program code comprising:

• computer-usable program code to, upon completing a first write job to a partition on a volume, make a copy of a volume change reference (VCR) value associated with the volume, the VCR value configured to change in a non-repeating manner each time content on the volume is modified;
• computer-usable program code to, prior to initiating a second write job to the partition, retrieve the copy and compare the copy to the VCR value.
• computer-usable program code to determine that a logical object on the partition was not modified between the first and second write jobs in the event the copy matches the VCR value;
• and
• computer-usable program code to determine that the logical object on the partition was modified between the first and second write jobs in the event the copy does not match the VCR value.

A system to enable an application to determine if logical objects on a volume are coherent with the last time the application wrote to the volume, the system comprising:

• an application to, upon completing a first write job to a partition on a volume, write a volume coherency set (VCS) to the partition, the VCS containing information for which coherency is desired;
• the application further configured to, upon completing the first write job to the partition, make a copy of a volume change reference (VCR) value associated with the volume and store the copy in an auxiliary memory associated with the volume;
• the application further configured to, prior to initiating a second write job to the partition, retrieve the copy from the auxiliary memory and compare it to the VCR value;
• and
• the application further configured to determine that the VCS was not modified between the first and second write jobs if the copy matches the VCR value, and that the VCS was modified between the first and second write jobs if the copy does not match the VCR value.