badsect(8)badsect(8)Namebadsect - create files to contain bad sectors
/etc/badsect bbdir sector ...
The command makes a file to contain a bad sector. Normally, bad sec‐
tors are made inaccessible by the standard formatter, which provides a
forwarding table for bad sectors to the driver. For further informa‐
tion, see If a driver supports the bad blocking standard it is much
preferable to use that method to isolate bad blocks, since the bad
block forwarding makes the pack appear perfect, and such packs can then
be copied with The technique used by this program is also less general
than bad block forwarding, as can't make amends for bad blocks in the
i-list of file systems or in swap areas.
On some disks, adding a sector which is suddenly bad to the bad sector
table currently requires the running of the standard DEC formatter.
Thus to deal with a newly bad block or on disks where the drivers do
not support the bad-blocking standard may be used to good effect.
The command is used on a quiet file system in the following way: First
mount the file system, and change to its root directory. Make a direc‐
tory BAD there. Run giving as argument the BAD directory followed by
all the bad sectors you wish to add. (The sector numbers must be rela‐
tive to the beginning of the file system, but this is not hard as the
system reports relative sector numbers in its console error messages.)
Then change back to the root directory, unmount the file system and run
on the file system. The bad sectors should show up in two files or in
the bad sector files and the free list. Have remove files containing
the offending bad sectors, but do not have it remove the BAD/nnnnn
files. This will leave the bad sectors in only the BAD files.
The command works by giving the specified sector numbers in a system
call, creating an illegal file whose first block address is the block
containing bad sector and whose name is the bad sector number. When it
is discovered by it will ask ``HOLD BAD BLOCK''? A positive response
will cause to convert the inode to a regular file containing the bad
If more than one sector that comprises a file system fragment is bad,
you should specify only one to as the blocks in the bad sector files
cover all the sectors in a file system fragment.
The command refuses to attach a block that resides in a critical area
or is out of range of the file system. A warning is issued if the
block is already in use.
See Alsobad144(8), format(8v), fsck(8)