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wd(4) [netbsd man page]

WD(4)							   BSD Kernel Interfaces Manual 						     WD(4)

wd -- WD100x compatible hard disk driver SYNOPSIS
wd* at atabus? drive ? flags 0x0000 wd* at umass? options WD_SOFTBADSECT DESCRIPTION
The wd driver supports hard disks that emulate the Western Digital WD100x. This includes standard MFM, RLL, ESDI, IDE, EIDE, and SATA drives. The flags are used only with controllers that support DMA operations and mode settings (like some pciide controllers). The lowest order nib- ble (rightmost digit) of the flags defines the PIO mode, the next four bits define the DMA mode and the third nibble defines the UltraDMA mode. For each set of four bits, the 3 lower bits define the mode to use and the last bit must be set to 1 for this setting to be used. For DMA and UDMA, 0xf (1111) means 'disable'. For example, a flags value of 0x0fac (1111 1010 1100) means 'use PIO mode 4, DMA mode 2, disable UltraDMA'. 0x0000 means "use whatever the drive claims to support." The kernel configuration option ``options WD_SOFTBADSECT'' enables a software managed bad-sector list which will prevent further accesses to sectors where an unrecoverable read error occurred. A user interface is provided by dkctl(8). Unlike the (historical) mechanisms provided by bad144(8) and badsect(8) the software list does neither support sector replacement nor is it saved across reboots. SEE ALSO
ata(4), intro(4), pciide(4), scsi(4), umass(4), wdc(4), atactl(8), dkctl(8) BUGS
The optional software bad sector list does not interoperate well with sector remapping features of modern disks. To let the disk remap a sector internally, the software bad sector list must be flushed or disabled before. BSD
August 30, 2004 BSD

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

badsect -- create files to contain bad sectors SYNOPSIS
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(8) 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(8) it will ask ``HOLD BAD BLOCK ?'' A positive response will cause fsck(8) to convert the inode to a regular file containing the bad block. 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. SEE ALSO
bad144(8), fsck(8) HISTORY
The badsect command appeared in 4.1BSD. BUGS
If more than one of the sectors in 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. BSD
June 5, 1993 BSD
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