VVDS stands for VSAM Volume Data Set and it’s a VSAM file that contains the information of all VSAM and SMS-managed non-VSAM data sets that reside on the volume where the VVDS file is allocated.
A VVDS is recognised by the restricted data set name SYS1.VVDS.Vvolser, where volser is the volume serial number of the volume on which the VVDS resides.
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VVDS Structure |
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Record |
Description |
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VVCR |
The VSAM Volume Control Record (VVCR) is the first logical record in a VVDS. The VVCR contains information for management of DASD space and the Base Catalog Structure (BCS) names, which currently have VSAM or SMS-managed non-VSAM data sets on the volume. The VVCR might have a pointer to an overflow VVCR. |
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Self-Describing VVR |
The VVDS self-describing VVR (VSAM Volume Record) is the second logical record in the VVDS. The self-describing VVR has the information that describes the VVDS. |
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VVR or NVR |
The remaining logical records in the VVDS can either be VVRs (VSAM Volume Records) for VSAM objects or NVRs (Non-VSAM Volume Records) for SMS-managed non-VSAM data sets. The hexadecimal RBA (Relative Byte Address) of the record is used as its key or identifier. |
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VVR or NVR |
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… |
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VVR or NVR |
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As a minimum, the VVDS contains two records:
- A VSAM Volume Control Record (VVCR)
- A VVDS self-describing volume record
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