diff options
Diffstat (limited to 'usr.sbin/bad144/bad144.8')
-rw-r--r-- | usr.sbin/bad144/bad144.8 | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/usr.sbin/bad144/bad144.8 b/usr.sbin/bad144/bad144.8 new file mode 100644 index 0000000..9ea8c88 --- /dev/null +++ b/usr.sbin/bad144/bad144.8 @@ -0,0 +1,186 @@ +.\" Copyright (c) 1980, 1988, 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)bad144.8 8.1 (Berkeley) 6/6/93 +.\" +.Dd June 6, 1993 +.Dt BAD144 8 +.Os BSD 4 +.Sh NAME +.Nm bad144 +.Nd read/write dec standard 144 bad sector information +.Sh SYNOPSIS +.Nm bad144 +.Op Fl c +.Op Fl f +.Op Fl v +.Ar disk +.Oo +.Ar sno +.Op Ar bad ... +.Oc +.Nm bad144 +.Fl a +.Op Fl c +.Op Fl f +.Op Fl v +.Ar disk +.Op Ar bad ... +.Sh DESCRIPTION +.Nm Bad144 +can be used to inspect the information stored on a disk that is used by +the disk drivers to implement bad sector forwarding. +.Pp +Available options: +.Pp +.Bl -tag -width Ds +.It Fl a +The argument list consists of new bad sectors to be added to an existing +list. +The new sectors are sorted into the list, +which must have been in order. +Replacement sectors are moved to accommodate the additions; +the new replacement sectors are cleared. +.It Fl c +Forces an attempt to copy the old sector to the replacement, +and may be useful when replacing an unreliable sector. +.It Fl f +For a RP06, RM03, RM05, Fujitsu Eagle, +or +.Tn SMD +disk on a Massbus, the +.Fl f +option may be used to mark the new bad sectors as ``bad'' +by reformatting them as unusable sectors. +This option is +.Em required unless +the sectors have already been marked bad, +or the system will not be notified that it should use the replacement sector. +This option may be used while running multiuser; it is no longer necessary +to perform format operations while running single-user. +.It Fl v +The entire process is described as it happens in gory detail if +.Fl v +(verbose) is given. +.El +.Pp +The format of +the information is specified by +.Tn DEC +standard 144, as follows. +The bad sector information is located in the first 5 even numbered sectors +of the last track of the disk pack. There are five identical copies of +the information, described by the +.Ar dkbad +structure. +.Pp +Replacement sectors are allocated starting with the first sector before +the bad sector information and working backwards towards the beginning +of the disk. A maximum of 126 bad sectors are supported. The position +of the bad sector in the bad sector table determines the replacement +sector to which it corresponds. +The bad sectors must be listed in ascending order. +.Pp +The bad sector information and replacement sectors are conventionally +only accessible through the ``c'' file system partition of the disk. If +that partition is used for a file system, the user is responsible for +making sure that it does not overlap the bad sector information or any +replacement sectors. +Thus, one track plus 126 sectors must be reserved to allow use +of all of the possible bad sector replacements. +.Pp +The bad sector structure is as follows: +.Bd -literal +struct dkbad { + long bt_csn; /* cartridge serial number */ + u_short bt_mbz; /* unused; should be 0 */ + u_short bt_flag; /* -1 => alignment cartridge */ + struct bt_bad { + u_short bt_cyl; /* bad sector cylinder number */ + u_short bt_trksec; /* track and sector number */ + } bt_bad[126]; +}; +.Ed +.Pp +Unused slots in the +.Ar bt_bad +array are filled with all bits set, a putatively +illegal value. +.Pp +.Nm Bad144 +is invoked by giving a device name (e.g. hk0, hp1, etc.). +With no optional arguments +it reads the first sector of the last track +of the corresponding disk and prints out the bad sector information. +It issues a warning if the bad sectors are out of order. +.Nm Bad144 +may also be invoked with a serial number for the pack and a list +of bad sectors. +It will write the supplied information into all copies +of the bad-sector file, replacing any previous information. +Note, however, that +.Nm bad144 +does not arrange for the specified sectors to be marked bad in this case. +This procedure should only be used to restore known bad sector information which +was destroyed. +.Pp +It is no longer necessary to reboot to allow the kernel +to reread the bad-sector table from the drive. +.Sh SEE ALSO +.Xr badsect 8 , +.Xr format 8 +.Sh BUGS +It should be possible to format disks on-line under +.Tn UNIX . +.Pp +It should be possible to mark bad sectors on drives of all type. +.Pp +On an 11/750, +the standard bootstrap drivers used to boot the system do +not understand bad sectors, +handle +.Tn ECC +errors, or the special +.Tn SSE +(skip sector) errors of RM80-type disks. +This means that none of these errors can occur when reading the file +.Pa /vmunix +to boot. Sectors 0-15 of the disk drive +must also not have any of these errors. +.Pp +The drivers which write a system core image on disk after a crash do not +handle errors; thus the crash dump area must be free of errors and bad +sectors. +.Sh HISTORY +The +.Nm +command appeared in +.Bx 4.1 . |