1DDRESCUE(1) User Commands DDRESCUE(1)
2
6 ddrescue - data recovery tool
7
9 ddrescue [options] infile outfile [mapfile]
10
12 GNU ddrescue - Data recovery tool. Copies data from one file or block
13 device to another, trying to rescue the good parts first in case of
14 read errors.
15 Always use a mapfile unless you know you won't need it. Without a map‐
17 file, ddrescue can't resume a rescue, only reinitiate it. NOTE: In
18 versions of ddrescue prior to 1.20 the mapfile was called 'logfile'.
19 The format is the same; only the name has changed.
20 If you reboot, check the device names before restarting ddrescue.
22 Don't use options '-F' or '-G' without reading the manual first.
23
25 -h, --help
26 display this help and exit
27 -V, --version
29 output version information and exit
30 -a, --min-read-rate=<bytes>
32 minimum read rate of good areas in bytes/s
33 -A, --try-again
35 mark non-trimmed, non-scraped as non-tried
36 -b, --sector-size=<bytes>
38 sector size of input device [default 512]
39 -B, --binary-prefixes
41 show binary multipliers in numbers [SI]
42 -c, --cluster-size=<sectors>
44 sectors to copy at a time [128]
45 -C, --complete-only
47 don't read new data beyond mapfile limits
48 -d, --idirect
50 use direct disc access for input file
51 -D, --odirect
53 use direct disc access for output file
54 -e, --max-bad-areas=[+]<n>
56 maximum number of [new] bad areas allowed
57 -E, --max-error-rate=<bytes>
59 maximum allowed rate of read errors per second
60 -f, --force
62 overwrite output device or partition
63 -F, --fill-mode=<types>
65 fill blocks of given types with data (?*/-+l)
66 -G, --generate-mode
68 generate approximate mapfile from partial copy
69 -H, --test-mode=<file>
71 set map of good/bad blocks from given mapfile
72 -i, --input-position=<bytes>
74 starting position of domain in input file [0]
75 -I, --verify-input-size
77 verify input file size with size in mapfile
78 -J, --verify-on-error
80 reread latest good sector after every error
81 -K, --skip-size=[<i>][,<max>]
83 initial,maximum size to skip on read error
84 -L, --loose-domain
86 accept an incomplete domain mapfile
87 -m, --domain-mapfile=<file>
89 restrict domain to finished blocks in <file>
90 -M, --retrim
92 mark all failed blocks as non-trimmed
93 -n, --no-scrape
95 skip the scraping phase
96 -N, --no-trim
98 skip the trimming phase
99 -o, --output-position=<bytes>
101 starting position in output file [ipos]
102 -O, --reopen-on-error
104 reopen input file after every read error
105 -p, --preallocate
107 preallocate space on disc for output file
108 -P, --data-preview[=<lines>]
110 show some lines of the latest data read [3]
111 -q, --quiet
113 suppress all messages
114 -r, --retry-passes=<n>
116 exit after <n> retry passes (-1=infinity) [0]
117 -R, --reverse
119 reverse the direction of all passes
120 -s, --size=<bytes>
122 maximum size of input data to be copied
123 -S, --sparse
125 use sparse writes for output file
126 -t, --truncate
128 truncate output file to zero size
129 -T, --timeout=<interval>
131 maximum time since last successful read
132 -u, --unidirectional
134 run all passes in the same direction
135 -v, --verbose
137 be verbose (a 2nd -v gives more)
138 -w, --ignore-write-errors
140 make fill mode ignore write errors
141 -x, --extend-outfile=<bytes>
143 extend outfile size to be at least this long
144 -X, --max-read-errors=<n>
146 maximum number of read errors allowed
147 -y, --synchronous
149 use synchronous writes for output file
150 -Z, --max-read-rate=<bytes>
152 maximum read rate in bytes/s
153 --ask ask for confirmation before starting the copy
155 --cpass=<n>[,<n>]
157 select what copying pass(es) to run
158 --delay-slow=<interval>
160 initial delay before checking slow reads [30]
161 --log-events=<file>
163 log significant events in <file>
164 --log-rates=<file>
166 log rates and error sizes in <file>
167 --log-reads=<file>
169 log all read operations in <file>
170 --mapfile-interval=[i][,i]
172 save/sync mapfile at given interval [auto]
173 --max-slow-reads=<n>
175 maximum number of slow reads allowed
176 --pause-on-error=<interval>
178 time to wait after each read error [0]
179 --pause-on-pass=<interval>
181 time to wait between passes [0]
182 --reset-slow
184 reset slow reads if rate rises above min
185 --same-file
187 allow infile and outfile to be the same file
188 Numbers may be in decimal, hexadecimal or octal, and may be followed by
190 a multiplier: s = sectors, k = 1000, Ki = 1024, M = 10^6, Mi = 2^20,
191 etc... Time intervals have the format 1[.5][smhd] or 1/2[smhd].
192 Exit status: 0 for a normal exit, 1 for environmental problems (file
194 not found, invalid flags, I/O errors, etc), 2 to indicate a corrupt or
195 invalid input file, 3 for an internal consistency error (eg, bug) which
196 caused ddrescue to panic.
197
199 Report bugs to bug-ddrescue@gnu.org
200 Ddrescue home page: http://www.gnu.org/software/ddrescue/ddrescue.html
201 General help using GNU software: http://www.gnu.org/gethelp
202
204 Copyright © 2018 Antonio Diaz Diaz. License GPLv2+: GNU GPL version 2
205 or later <http://gnu.org/licenses/gpl.html>
206 This is free software: you are free to change and redistribute it.
207 There is NO WARRANTY, to the extent permitted by law.
208
210 The full documentation for ddrescue is maintained as a Texinfo manual.
211 If the info and ddrescue programs are properly installed at your site,
212 the command
213 info ddrescue
215 should give you access to the complete manual.
217ddrescue 1.23 February 2018 DDRESCUE(1)