Disk Track Format

URz supports the following requirements on the disk track format, which must be ensured by the user. URz cannot detect exceptions to these requirements. The primary storage system will abort the URz initial copy operation if the track format for both the primary data volume and secondary data volume does not meet the following requirements.

The TCz primary data volume and secondary data volume must have the same track format.

Record zero (R0) must be standard format, with key length of zero and data length of eight. The primary storage system will abort the initial copy operation if R0 is not standard format.

The CCHH (logical cylinder address and logical head address) of R0 must be identical to the physical cylinder address and physical head address of the track.

The CCHH of each user record in a track must be unique.

One-to-One Volume Copy Operations

URz requires a one-to-one relationship between the volumes of the volume pairs. A volume (LDEV) can only be assigned to one URz pair at a time. However, when creating a URz pair for delta resync operation, you can specify the secondary data volume of a URz pair that is not for delta resync operation as the secondary data volume of the URz pair for delta resync operation. In that case, you need to create a mirror the delta-resync pair and the non-delta- resync pair. For detailed information about delta resync operation, see section URz Delta Resync Operation and TCz Synchronous (3DC Multi-target Configuration).

Note: URz does not support operations in which one primary data volume is copied to more than one secondary data volume, or more than one primary data volume is copied to one secondary data volume.

Because URz operates on volumes rather than on files, multivolume files require special attention. For complete duplication and recovery of a multivolume file (e.g., a large database file which spans several volumes), make sure that all volumes of the file are copied to URz secondary data volume, and use URz to ensure update sequence consistency across this group of secondary data volume.

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Chapter 3 Preparing for Universal Replicator z/OS Operations

Hitachi Universal Replicator for IBM /OS User’s Guide

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Hitachi MP-96RD625-01 manual Disk Track Format, One-to-One Volume Copy Operations