badsect(8) [opendarwin man page]

BADSECT(8)						    BSD System Manager's Manual 						BADSECT(8)

NAME

     badsect -- create files to contain bad sectors

SYNOPSIS

     /etc/badsect bbdir sector ...

DESCRIPTION

     Badsect makes a file to contain a bad sector.  Normally, bad sectors are made inaccessible by the standard formatter, which provides a for-
     warding table for bad sectors to the driver; see bad144(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 dd(1).  The technique used by this program is also less general than bad block forwarding, as badsect 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 badsect may be used to good
     effect.

     Badsect is used on a quiet file system in the following way: First mount the file system, and change to its root directory.  Make a directory
     BAD there.  Run badsect 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 mes-
     sages.)  Then change back to the root directory, unmount the file system and run fsck(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 fsck 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.

     Badsect works by giving the specified sector numbers in a mknod(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 fsck it will ask ``HOLD BAD BLOCK ?'' A posi-
     tive response will cause fsck to convert the inode to a regular file containing the bad block.

SEE ALSO

     bad144(8), fsck(8), format(8)

DIAGNOSTICS

     Badsect 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.

BUGS

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

HISTORY

     The badsect command appeared in 4.1BSD.

4th Berkeley Distribution					   June 5, 1993 					 4th Berkeley Distribution

Check Out this Related Man Page

DISKPART(8)						      System Manager's Manual						       DISKPART(8)

NAME

       diskpart - calculate default disk partition sizes

SYNOPSIS

       /usr/sbin/diskpart [ -p ] [ -d ] disk-type

DESCRIPTION

       Diskpart  is  used to calculate the disk partition sizes based on the default rules used at Berkeley.  If the -p option is supplied, tables
       suitable for inclusion in a device driver are produced.	If the -d option is supplied, an entry suitable for inclusion in the disk descrip-
       tion  file  /etc/disktab  is  generated; c.f.  disktab(5).  On disks that use bad144-style bad-sector forwarding, space is left in the last
       partition on the disk for a bad sector forwarding table.  The space reserved is one track for the replicated copies of the table and suffi-
       cient tracks to hold a pool of 126 sectors to which bad sectors are mapped.  For more information, see bad144(8).

       The  disk  partition sizes are based on the total amount of space on the disk as given in the table below (all values are supplied in units
       of 512 byte sectors).  The `c' partition is, by convention, used to access the entire physical disk.  The device driver tables include  the
       space  reserved	for  the  bad sector forwarding table in the `c' partition; those used in the disktab and default formats exclude reserved
       tracks.	In normal operation, either the `g' partition is used, or the `d', `e', and `f' partitions are used.  The `g' and  `f'	partitions
       are  variable-sized,  occupying	whatever  space  remains  after  allocation of the fixed sized partitions.  If the disk is smaller than 20
       Megabytes, then diskpart aborts with the message ``disk too small, calculate by hand''.

	    Partition  20-60 MB  61-205 MB  206-355 MB	356+ MB
	    a	       15884	 15884	    15884	15884
	    b	       10032	 33440	    33440	66880
	    d	       15884	 15884	    15884	15884
	    e	       unused	 55936	    55936	307200
	    h	       unused	 unused     291346	291346

       If an unknown disk type is specified, diskpart will prompt for the required disk geometry information.

SEE ALSO

       disktab(5), bad144(8)

BUGS

       Certain default partition sizes are based on historical artifacts (e.g. RP06), and may result in unsatisfactory layouts.

       When using the -d flag, alternate disk names are not included in the output.

4th Berkeley Distribution					 November 17, 1996						       DISKPART(8)

Linux and UNIX Man Pages

badsect(8) [opendarwin man page]

Check Out this Related Man Page