An S-VOL's consistency refers to whether S-VOL data is identical to data in the P-VOL. This is dependent on your Fence Level setting, which determines whether data is copied to the P-VOL if an error occurs during an update to the S-VOL.
The following table shows S-VOL consistency information, based on pair status and the P-VOL fence level setting.
| S-VOL status for CCI | Split type | Fence level for CCI | Consistency of S-VOL |
|---|---|---|---|
| SMPL | - | data, status, never | Not consistent. The S-VOL does not belong to a pair. Even if you have created a pair using this volume, if the pair status is still SMPL, you must regard its data as not consistent with the P-VOL. |
| COPY | - | data, status, never | Not consistent. The S-VOL is not synchronized because not all tracks have been copied from the P-VOL yet. This S-VOL must be initialized (or copied from the P-VOL at a later time). |
| PAIR | - | data, status | Consistent. The S-VOL is synchronized with its P-VOL. |
| never | Needs to be analyzed. The S-VOL requires further analysis to determine its level of consistency. | ||
| PSUE | Initial copy failed* | data, status, never | Not consistent. The S-VOL is not synchronized because not all tracks have been copied from the P-VOL yet. The S-VOL must be initialized (or copied from the P-VOL at a later time). |
| PSUS | S-VOL by operator* | data, status, never | Suspect. The S-VOL is not synchronized with its P-VOL if any write I/Os were issued to the P-VOL after the pair was split. The pair must be released and re-created by running the paircreate command without specifying the -nocopy option. However, if it is certain that the data in the P-VOL has not been changed at all, run the paircreate command with the -nocopy option to re-create the pair. |
| PSUS and PSUE | All other types* | data | Consistent. The S-VOL is synchronized with its P-VOL. |
| status, never | Suspect. The S-VOL is not synchronized with its P-VOL if any write I/Os were issued to the P-VOL after the pair was split. Restore the consistency of the S-VOL and update it, if required. The time of suspension indicated in the LUT column (last update date) by running the pairdisplay command with the -fe option | ||
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Legend: Never: No copy Data: Data in the secondary volume Status: Status of the secondary volume * When you run the pairdisplay command with the -fe option, the type of PSUS or PSUE is displayed in hexadecimal in the ST column. For example,
For pairs whose output results of the pairdisplay command for Fence in CCI is never, further analysis is required to determine the S-VOL consistency. This can be determined by using sense information transferred by host failover, or by comparing the contents of the S-VOL with other files that are confirmed to be consistent (for example, database log files). The S-VOLs should be recovered using the files that are confirmed to be consistent. Note: Actual data recovery must be done using recovery point data in the database operation log. |
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