.TH CHUCK 8
.CT 1 sa_nonmortals
.SH NAME
chuck \- a file system checking program
.SH SYNOPSIS
.B /etc/chuck
[
.I option ...
]
.I device
.PP
.B /etc/chuck
.B -M
.I blocks
.I device
.PP
.B /etc/upchuck
[
.B -w
] [
.B -p
.I program
]
.SH DESCRIPTION
.PP
.I Chuck
checks and optionally repairs the file system on the named
.I device.
It is normally invoked by
.I upchuck
by
.IR rc (8)
during reboots.
The
.B -w
flag to
.I upchuck
is passed on to
.I program.
If
.I program
is not present, the default is
.FR /etc/chuck .
(Try, as super-user,
.B "/etc/upchuck -p /bin/echo
to see the normal arguments to
.IR chuck .)
If
.I upchuck
can read the raw version of
.I device,
it will, except for the root file system.
.PP
The options are
.TP
.B -w
Try to do standard repairs.
.TP
.BI -b " blocksize
Specify file system block size; default is 4096.
.TP
.B -i
Interactive.
Ask approval for each change.
.TP
.BI -I " inode ...
.br
.ns
.TP
.BI -B " block ...
Report on inodes or blocks specified by number.
.TP
.B -v
Verbose.
Give more commentary.
.PP
.I Chuck
can also make a new file system:
.B "chuck -M"
.I size device
makes a bitmapped file system (only)
of
.I size
4096-byte blocks
on
.IR device .
It asks approval before writing.
.SH FILES
.F /etc/fstab
.SH "SEE ALSO"
.IR fstab (5), 
.IR filsys (5), 
.IR fsck (8),
.IR reboot (8)
.SH BUGS
.I Chuck
does not replace real expertise.
It will not automatically repair a file system with duplicate blocks.
In complicated situations it may have to be run
several times to get complete consistency.
.br
It will not recover from I/O errors in reading the inodes,
and does not yet extend
.F lost+found
when necessary.
.br
It uses memory freely (about 12 bytes per file system block
and 84 bytes per inode).
.br
.I Chuck
is still experimental,
and acts the part.
Error messages are usually inscrutable.
.br
It believes even preposterous super-blocks and
consequently can get core images.