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ABCs of z/OS System Programming Volume 3 - IBM Redbooks

ABCs of z/OS System Programming Volume 3 - IBM Redbooks

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to use this specification or the specification in the CICS FCT. The BWO type is stored in<br />

the ICF catalog.<br />

Backup-while-open <strong>of</strong> a forward recoverable data set<br />

If you use the DSS BWO processing for a forward recoverable data set, CICS will log the start<br />

and end <strong>of</strong> the copy/backup operation. The data set can then be fully recovered from this<br />

backup.<br />

For information about BWO processing, see z/<strong>OS</strong> DFSMSdss Storage Administration<br />

Reference, SC35-0424.<br />

Recover a CICS VSAM data set<br />

Sometimes it is necessary to recover a data set, for example if it became broken.<br />

► Recovery <strong>of</strong> a non-recoverable data set<br />

Data sets with LOG(NONE) are considered non-recoverable. To recover such a data set,<br />

restore the last backup <strong>of</strong> the data set. All updates to this data set after the backup was<br />

taken are lost. If the backup was taken after a transaction failed (did not commit), the data<br />

in the backup might be inconsistent.<br />

► Recovery <strong>of</strong> a backward recoverable data set<br />

Data sets with the LOG(NONE) attribute are considered backward recoverable. To recover<br />

such a data set, restore the last backup <strong>of</strong> the data set. All updates to this data set after<br />

the backup was taken are lost. The data in the backup is consistent.<br />

► Recovery <strong>of</strong> a forward recoverable data set<br />

Data sets with LOG(ALL) and a log stream assigned are forward recoverable. Restore the<br />

last backup <strong>of</strong> the data set. Then run a tool like CICS VSAM Recovery (CICSVR), which<br />

uses the forward recovery log to redrive all committed updates until the data set became<br />

broken. No updates are lost.<br />

416 <strong>ABCs</strong> <strong>of</strong> z/<strong>OS</strong> <strong>System</strong> <strong>Programming</strong> <strong>Volume</strong> 3

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