V8/usr/man/man8/rarepl.8

.TH RAREPL 8
.SH NAME
rarepl, rarct \- replace bad blocks on MSCP disks
.SH SYNOPSIS
.B /etc/rarct
[
.B \-c
] [
.B \-h
]
special ...
.br
.B /etc/rarepl
special
lbn ...
.SH DESCRIPTION
.I Rarct
prints status information
about MSCP disk drives
(drives such as the RA60 and RA81
on controllers like the UDA50).
Normally the replacement table (RCT)
is listed,
as lines of the form
.IP
rbn:\0flags:\0lbn
.PP
where
.I rbn
is the replacement block number,
.I lbn
is the logical block number
replaced by
.IR rbn ,
and
.I flags
are constructed from the following bits:
.TP
.PD 0
01
alternate (not primary) replacement block
.TP
02
normal, allocated replacement block
.TP
04
this replacement block is bad
.TP
010
this replacement block does not exist
.PD
.PP
Entries whose
.I flags
are zero,
indicating a good,
unused replacement block,
are not listed.
.PP
The
.B \-h
option
prints some header data
from the first block of the RCT.
UNIX makes no use of this info.
.B \-c
prints geometry info for the drive.
Either option
suppresses
the RCT listing.
.PP
.I Rarepl
causes logical block
.I lbn
on device
.I dev
to be marked as bad
and replaced.
The nearest available replacement block
is used.
The contents of
.I lbn
are copied into the replacement block if possible;
if
.I lbn
is unreadable,
the replacement block
is initialized with zeroes.
.PP
Both programs
work only
on the raw devices.
.I Rarepl
should be used only
on a device
which covers the entire drive
(usually partition 7).
.SH SEE ALSO
ra(4)
.SH BUGS
On the UDA50,
the RCT exists
only so programs in the host can look at it;
the controller ignores its contents.
There is no way to read the controller's `real' forwarding data,
only a way to set it for a particular block.
Hence if the RCT is corrupted,
the disk may still be used,
but must be reformatted
before additional bad blocks are remapped.