4.3BSD-Reno/share/man/cat8/badsect.0

BADSECT(8)		      1990		       BADSECT(8)



NNAAMMEE
     badsect - create files to contain bad sectors

SSYYNNOOPPSSIISS
     //eettcc//bbaaddsseecctt bbdir sector ...

DDEESSCCRRIIPPTTIIOONN
     _B_a_d_s_e_c_t makes a file to contain a bad sector.  Normally, bad
     sectors are made inaccessible by the standard formatter,
     which provides a forwarding table for bad sectors to the
     driver; see _b_a_d_1_4_4(8) for details.  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 _d_d(1).  The technique used by this program is
     also less general than bad block forwarding, as _b_a_d_s_e_c_t
     can't make amends for bad blocks in the i-list of file sys-
     tems 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 stan-
     dard DEC formatter.  Thus to deal with a newly bad block or
     on disks where the drivers do not support the bad-blocking
     standard _b_a_d_s_e_c_t may be used to good effect.

     _B_a_d_s_e_c_t is used on a quiet file system in the following way:
     First mount the file system, and change to its root direc-
     tory.  Make a directory BAD there.  Run _b_a_d_s_e_c_t giving as
     argument the BAD directory followed by all the bad sectors
     you wish to add.  (The sector numbers must be relative 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 _f_s_c_k(8) on the file system.
     The bad sectors should show up in two files or in the bad
     sector files and the free list.  Have _f_s_c_k remove files con-
     taining the offending bad sectors, but ddoo nnoott have it remove
     the BAD/_n_n_n_n_n files.  This will leave the bad sectors in
     only the BAD files.

     _B_a_d_s_e_c_t works by giving the specified sector numbers in a
     _m_k_n_o_d(2) 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
     _f_s_c_k it will ask ``HOLD BAD BLOCK''?  A positive response
     will cause _f_s_c_k to convert the inode to a regular file con-
     taining the bad block.

SSEEEE AALLSSOO
     bad144(8), fsck(8), format(8V)





Printed 7/27/90               June				1






BADSECT(8)		      1990		       BADSECT(8)



DDIIAAGGNNOOSSTTIICCSS
     _B_a_d_s_e_c_t 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.

BBUUGGSS
     If more than one sector which comprise a file system frag-
     ment are bad, you should specify only one of them to _b_a_d_-
     _s_e_c_t, as the blocks in the bad sector files actually cover
     all the sectors in a file system fragment.













































Printed 7/27/90               June				2