# System Parameters

'VW'= | Verify Write

## Description

Verifies all data file writes by re-reading after a write to check data integrity. The value set in 'VW' defines the number of retries before a data write error is generated.

#### Note:
'VW' can be helpful in tracking down hardware-related data corruption problems. (There is some impact on system performance.)

TCB( ) returns the following values for this parameter:

> TCB(63) - Number of writes verified
> TCB(65) - Number of writes mis-compares

## Default

'VW'=0

## See Also

TCB( ) Return Task Information