radisk(8)radisk(8)Nameradisk - Digital Storage Architecture (DSA) disk maintenance
Syntax
/etc/radisk
radisk-c LBN length special
radisk -e special
radisk -n special
radisk -r LBN special
radisk -s LBN length special
Description
The Digital Storage Architecture (DSA) disk maintenance program pro‐
vides the essential functions to manage DSA disk devices. The 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, -e, -n, and -r options and
indicates an unmounted c partition of a character device special file.
Options
The following options may be set with
-c Clears 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 an 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 command.
The command affects the integrity of the data on a disk and should
be followed by a file system restore if data is affected.
-e Sets the exclusive access attribute associated with the specified
disk. This attribute is provided by multihost controllers to
restrict access to a disk to one host. The command will return a
failure status if the disk is already exclusively associated with
another host or the underlying controller does not provide multi‐
host support. If the command is issued to a disk that is cur‐
rently mounted and the command fails, the disk will no longer be
online to this host. For this reason the -e option should not be
issued to a disk that is mounted.
n Clears the exclusive access attribute associated with the speci‐
fied disk. If the controller provides multihost support and the
exclusive access attribute is not set for a particular disk, it
would be possible for the disk to be accessed by more than one
host. The command will return a failure status if the disk is not
currently and exclusively associated with this host or the under‐
lying controller does not provide multihost support.
-r Replaces a block on the disk specified by LBN. See Restrictions.
-s Starts 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 spec‐
ified with the 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 option
will accept any valid partition on the disk. This allows any par‐
tition to be scanned without scanning the entire disk and ensures
that the specified partition is free of bad blocks. As an example,
indicates the h partition of the third logical disk unit.
Diagnostics
The 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 using the and options of the pro‐
gram. If you are in multiuser mode, hangs the system and cannot be
killed. If this happens, you must reboot.
The option is supported only with those DSA disks which use host-initi‐
ated dynamic bad block replacement.
The and options are only supported on controllers that provide multi-
host support. These options are only supported on HSC Version 5.00 or
later.
See Alsodkio(4), ra(4), sdc(4), chpt(8), mount(8), restore(8)
Guide to System Disk Maintenance
4th Berkeley Distributionradisk(8)
