NAME

radisk − DSA disk maintenance

SYNTAX

/etc/radisk radisk −c LBN length special
radisk −r LBN special
radisk −s LBN length special

DESCRIPTION

The DSA disk maintenance program radisk provides the essential functions to manage DSA (DIGITAL Storage Architecture) disk devices. The radisk command must be used on unmounted disk partitions to insure correct results.

The LBN is a decimal number that represents the logical block number as reported in the errorlog file.  The LBN is the actual disk block number starting from the beginning of the disk. 

The length is a decimal number that indicates how many (512 byte) blocks to process.  The length specified may be −1 to indicate the last block of the specified partition. 

The special file specified is used with −c and −r options and indicates an unmounted c partition of a character device special file. 

OPTIONS

The following options may be set with radisk.

-cClears a forced error indicator on the range of specified LBNs.  The forced error condition indicates that the data in the disk block is bad.  The disk block is good, but the data can not be read without getting a error detection code (EDC) error.  This option will cause the forced error condition to be removed.  After the forced error indicator is cleared, the EDC error will not be reported nor will the data be marked as bad. 

All indications that the data is corrupt are lost.  The data should be restored either by manual methods or with the restore command. The radisk command affects the integrity of the data on a disk and should be followed by a file system restore if data is affected.

-rReplaces a block on the disk specified by LBN. See RESTRICTIONS. 

-sStarts a scan for bad blocks on the specified area on a disk. Bad blocks are disk blocks that have data transfer errors to the extent that they cannot be relied on.  When a bad block is found, it is replaced and the bad block’s LBN is reported.  The LBN specified with the −s option can be 0 to indicate the first block in the specified partition.  If 0 is specified however, the program starts searching from the first block of the partition. The −s option will accept any valid partition on the disk. This allows any partition to be scanned without scanning the entire disk and ensures that the specified partition is free of bad blocks. As an example, /dev/rra3h indicates the h partition of the third logical disk unit. 

DIAGNOSTICS

The radisk command generates messages when the user is not privileged, when the LBN is not in the specified partition, and when the length exceeds the size of the partition.

RESTRICTIONS

You must be in single-user mode when running the radisk program.  If you are in multiuser mode, radisk hangs the system and cannot be killed.  If this happens, you must reboot.

The −r option is supported only with those DSA disks which use host-initiated dynamic bad block replacement. 

SEE ALSO

dkio(4), ra(4), sdc(4), chpt(8), mount(8), restore(8)
Guide to System Disk Maintenance