1 /BLOCKS
/BLOCKS={(START:n, COUNT:x, END:y,) FILE_SYSTEM, ALL} Directs the system to compare only the range specified. The options are the following: START:n Number of the first block to be analyzed. The default is the first block. COUNT:x Number of blocks to be analyzed. You can use this option in combination with or instead of the END option. END:y Number of the last block to be analyzed. The default is the last block of the volume. FILE_ Blocks currently in use by valid files on the disk. SYSTEM This is the default. ALL All blocks on the disk. You can specify START,END,COUNT and either ALL or FILE_SYSTEM. For example, if you specify /BLOCKS=(START,END,COUNT:100,ALL), the software checks the first 100 blocks on the disk, whether or not the file system is using them. If you specify /BLOCKS=(START,END,COUNT:100,FILE_SYSTEM), the software checks only those blocks that valid files on the disk are using.
2 /BRIEF
Displays only the logical block number (LBN) if the data in a block is found to be different. Without this qualifier, if differences exist for an LBN, the hexadecimal data of that block will be displayed for each member.
3 /IGNORE
/IGNORE [NO]IGNORE Ignore "special" files that are likely to have some blocks with different data. These differences, however, are not unusual and can, therefore, be ignored. Other special files are the following: SWAPFILE*.* PAGEFILE*.* SYSDUMP.DMP SYS$ERRLOG.DMP IGNORE is the default.
4 /OUTPUT
/OUTPUT=filename Output the information to the specified file.
5 /STATISTICS
Display only the file header and footer. The best use of this qualifier is with the /OUTPUT qualifier.