.\" Copyright (c) 2006 Ulrich Spoerlein .\" 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. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. .\" .\" $FreeBSD$ .\" .Dd October 1, 2013 .Dt RECOVERDISK 1 .Os .Sh NAME .Nm recoverdisk .Nd recover data from hard disk or optical media .Sh SYNOPSIS .Nm .Op Fl b Ar bigsize .Op Fl r Ar readlist .Op Fl s Ar interval .Op Fl w Ar writelist .Ar source .Op Ar destination .Sh DESCRIPTION The .Nm utility reads data from the .Ar source file until all blocks could be successfully read. If .Ar destination was specified all data is being written to that file. It starts reading in multiples of the sector size. Whenever a block fails, it is put to the end of the working queue and will be read again, possibly with a smaller read size. .Pp By default it uses block sizes of roughly 1 MB, 32kB, and the native sector size (usually 512 bytes). These figures are adjusted slightly, for devices whose sectorsize is not a power of 2, e.g., audio CDs with a sector size of 2352 bytes. .Pp The options are as follows: .Bl -tag -width indent .It Fl b Ar bigsize The size of reads attempted first. The middle pass is roughly the logarithmic average of the bigsize and the sectorsize. .It Fl r Ar readlist Read the list of blocks and block sizes to read from the specified file. .It Fl s Ar interval How often we should update the writelist file while things go OK. The default is 60 and the unit is "progress messages" so if things go well, this is the same as once per minute. .It Fl w Ar writelist Write the list of remaining blocks to read to the specified file if .Nm is aborted via .Dv SIGINT . .El .Pp The .Fl r and .Fl w options can be specified together. Especially, they can point to the same file, which will be updated on abort. .Sh OUTPUT The .Nm utility prints several columns, detailing the progress .Bl -tag -width remaining .It Va start Starting offset of the current block. .It Va size Read size of the current block. .It Va len Length of the current block. .It Va state Is increased for every failed read. .It Va done Number of bytes already read. .It Va remaining Number of bytes remaining. .It Va "% done" Percent complete. .El .Sh EXAMPLES .Bd -literal # recover data from failing hard drive ada3 recoverdisk /dev/ada3 /data/disk.img # clone a hard disk recoverdisk /dev/ada3 /dev/ada4 # read an ISO image from a CD-ROM recoverdisk /dev/cd0 /data/cd.iso # continue reading from a broken CD and update the existing worklist recoverdisk -r worklist -w worklist /dev/cd0 /data/cd.iso # recover a single file from the unreadable media recoverdisk /cdrom/file.avi file.avi # If the disk hangs the system on read-errors try: recoverdisk -b 0 /dev/ada3 /somewhere .Ed .Sh SEE ALSO .Xr dd 1 , .Xr ada 4 , .Xr cam 4 , .Xr cd 4 , .Xr da 4 .Sh HISTORY The .Nm utility first appeared in .Fx 7.0 . .Sh AUTHORS .An -nosplit The original implementation was done by .An Poul-Henning Kamp Aq phk@FreeBSD.org with minor improvements from .An Ulrich Sp\(:orlein Aq uqs@FreeBSD.org . .Pp This manual page was written by .An Ulrich Sp\(:orlein . .Sh BUGS Reading from media where the sectorsize is not a power of 2 will make all 1 MB reads fail. This is due to the DMA reads being split up into blocks of at most 128kB. These reads then fail if the sectorsize is not a divisor of 128kB. When reading a full raw audio CD, this leads to roughly 700 error messages flying by. This is harmless and can be avoided by setting .Fl b to no more than 128kB. .Pp .Nm needs to know about read errors as fast as possible, i.e. retries by lower layers will usually slow down the operation. When using .Xr cam 4 attached drives, you may want to set kern.cam.XX.retry_count to zero, e.g.: .Bd -literal # sysctl kern.cam.ada.retry_count=0 # sysctl kern.cam.cd.retry_count=0 # sysctl kern.cam.da.retry_count=0 .Ed .\".Pp .\"When reading from optical media, a bug in the GEOM framework will .\"prevent it from seeing that the media has been removed. .\"The device can still be opened, but all reads will fail. .\"This is usually harmless, but will send .\".Nm .\"into an infinite loop.