1DDRESCUE(1) User Commands DDRESCUE(1)
2
6 ddrescue - data recovery tool
7
9 ddrescue [options] infile outfile [mapfile]
10
12 GNU ddrescue is a data recovery tool. It copies data from one file or
13 block device (hard disc, cdrom, etc) to another, trying to rescue the
14 good parts first in case of 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. Be careful to
18 not specify by mistake an old mapfile from an unrelated rescue.
19 NOTE: In versions of ddrescue prior to 1.20 the mapfile was called
21 'logfile'. The format is the same; only the name has changed.
22 If you reboot, check the device names before restarting ddrescue.
24 Don't use options '-F' or '-G' without reading the manual first.
25
27 -h, --help
28 display this help and exit
29 -V, --version
31 output version information and exit
32 -a, --min-read-rate=<bytes>
34 minimum read rate of good areas in bytes/s
35 -A, --try-again
37 mark non-trimmed, non-scraped as non-tried
38 -b, --sector-size=<bytes>
40 sector size of input device [default 512]
41 -B, --binary-prefixes
43 show binary multipliers in numbers [SI]
44 -c, --cluster-size=<sectors>
46 sectors to copy at a time [128]
47 -C, --complete-only
49 don't read new data beyond mapfile limits
50 -d, --idirect
52 use direct disc access for input file
53 -D, --odirect
55 use direct disc access for output file
56 -e, --max-bad-areas=[+]<n>
58 maximum number of [new] bad areas allowed
59 -E, --max-error-rate=<bytes>
61 maximum allowed rate of read errors per second
62 -f, --force
64 overwrite output device or partition
65 -F, --fill-mode=<types>
67 fill blocks of given types with data (?*/-+l)
68 -G, --generate-mode
70 generate approximate mapfile from partial copy
71 -H, --test-mode=<file>
73 set map of good/bad blocks from given mapfile
74 -i, --input-position=<bytes>
76 starting position of domain in input file [0]
77 -I, --verify-input-size
79 verify input file size with size in mapfile
80 -J, --verify-on-error
82 reread latest good sector after every error
83 -K, --skip-size=[<i>][,<max>]
85 initial,maximum size to skip on read error
86 -L, --loose-domain
88 accept unordered domain mapfile with gaps
89 -m, --domain-mapfile=<file>
91 restrict domain to finished blocks in <file>
92 -M, --retrim
94 mark all failed blocks as non-trimmed
95 -n, --no-scrape
97 skip the scraping phase
98 -N, --no-trim
100 skip the trimming phase
101 -o, --output-position=<bytes>
103 starting position in output file [ipos]
104 -O, --reopen-on-error
106 reopen input file after every read error
107 -p, --preallocate
109 preallocate space on disc for output file
110 -P, --data-preview[=<lines>]
112 show some lines of the latest data read [3]
113 -q, --quiet
115 suppress all messages
116 -r, --retry-passes=<n>
118 exit after <n> retry passes (-1=infinity) [0]
119 -R, --reverse
121 reverse the direction of all passes
122 -s, --size=<bytes>
124 maximum size of input data to be copied
125 -S, --sparse
127 use sparse writes for output file
128 -t, --truncate
130 truncate output file to zero size
131 -T, --timeout=<interval>
133 maximum time since last successful read
134 -u, --unidirectional
136 run all passes in the same direction
137 -v, --verbose
139 be verbose (a 2nd -v gives more)
140 -w, --ignore-write-errors
142 make fill mode ignore write errors
143 -W, --compare-before-write
145 omit superfluous writes in rescue mode
146 -x, --extend-outfile=<bytes>
148 extend outfile size to be at least this long
149 -X, --max-read-errors=<n>
151 maximum number of read errors allowed
152 -y, --synchronous
154 use synchronous writes for output file
155 -Z, --max-read-rate=<bytes>
157 maximum read rate in bytes/s
158 --ask ask for confirmation before starting the copy
160 --command-mode
162 execute commands from standard input
163 --cpass=<range>
165 select what copying pass(es) to run
166 --delay-slow=<interval>
168 initial delay before checking slow reads [30]
169 --log-events=<file>
171 log significant events in <file>
172 --log-rates=<file>
174 log rates and error sizes in <file>
175 --log-reads=<file>
177 log all read operations in <file>
178 --mapfile-interval=[i][,i]
180 save/sync mapfile at given interval [auto]
181 --max-slow-reads=<n>
183 maximum number of slow reads allowed
184 --pause-on-error=<interval>
186 time to wait after each read error [0]
187 --pause-on-pass=<interval>
189 time to wait between passes [0]
190 --reset-slow
192 reset slow reads if rate rises above min
193 --same-file
195 allow infile and outfile to be the same file
196 Numbers may be in decimal, hexadecimal, or octal, and may be followed
198 by a multiplier: s = sectors, k = 1000, Ki = 1024, M = 10^6, Mi = 2^20,
199 etc... Time intervals have the format 1[.5][smhd] or 1/2[smhd].
200 Exit status: 0 for a normal exit, 1 for environmental problems (file
202 not found, invalid command line options, I/O errors, etc), 2 to indi‐
203 cate a corrupt or invalid input file, 3 for an internal consistency er‐
204 ror (e.g., bug) which caused ddrescue to panic.
205
207 Report bugs to bug-ddrescue@gnu.org
208 Ddrescue home page: http://www.gnu.org/software/ddrescue/ddrescue.html
209 General help using GNU software: http://www.gnu.org/gethelp
210
212 Copyright © 2023 Antonio Diaz Diaz. License GPLv2+: GNU GPL version 2
213 or later <http://gnu.org/licenses/gpl.html>
214 This is free software: you are free to change and redistribute it.
215 There is NO WARRANTY, to the extent permitted by law.
216
218 The full documentation for ddrescue is maintained as a Texinfo manual.
219 If the info and ddrescue programs are properly installed at your site,
220 the command
221 info ddrescue
223 should give you access to the complete manual.
225GNU ddrescue 1.27 January 2023 DDRESCUE(1)