1 FSCK(1M) Maintenance Commands FSCK(1M)
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3
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5 NAME
6 fsck - check and repair file systems
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8 SYNOPSIS
9 fsck [-F FSType] [-m] [-V] [-v] [special]...
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12 fsck [-F FSType] [-n | N | y | Y] [-V] [-v]
13 [-o FSType-specific-options] [special]...
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15
16 DESCRIPTION
17 fsck audits and interactively repairs inconsistent file system
18 conditions. If the file system is inconsistent the default action for
19 each correction is to wait for the user to respond yes or no. If the
20 user does not have write permission fsck defaults to a no action. Some
21 corrective actions will result in loss of data. The amount and severity
22 of data loss can be determined from the diagnostic output.
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25 FSType-specific-options are options specified in a comma-separated (with
26 no intervening spaces) list of options or keyword-attribute pairs for
27 interpretation by the FSType-specific module of the command.
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30 special represents the character special device on which the file
31 system resides, for example, /dev/rdsk/c1t0d0s7. Note: the character
32 special device, not the block special device, should be used. fsck will
33 not work if the block device is mounted.
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36 If no special device is specified fsck checks the file systems listed
37 in /etc/vfstab. Those entries in /etc/vfstab which have a character
38 special device entry in the fsckdev field and have a non-zero numeric
39 entry in the fsckpass field will be checked. Specifying -F FSType limits
40 the file systems to be checked to those of the type indicated.
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43 If special is specified, but -F is not, the file system type will be
44 determined by looking for a matching entry in /etc/vfstab. If no entry
45 is found, the default local file system type specified in
46 /etc/default/fs will be used.
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49 If a file system type supports parallel checking, for example, ufs,
50 some file systems eligible for checking may be checked in parallel.
51 Consult the file system-specific man page (for example, fsck_ufs(1M))
52 for more information.
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54 OPTIONS
55 The following generic options are supported:
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57 -F FSType
58 Specify the file system type on which to operate.
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61 -m
62 Check but do not repair. This option checks that the file system is
63 suitable for mounting, returning the appropriate exit status. If
64 the file system is ready for mounting, fsck displays a message such
65 as:
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67 ufs fsck: sanity check: /dev/rdsk/c0t3d0s1 okay
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72 -n | -N
73 Assume a no response to all questions asked by fsck; do not open
74 the file system for writing.
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77 -V
78 Echo the expanded command line but do not execute the command. This
79 option may be used to verify and to validate the command line.
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82 -v
83 Enables verbose output. Might not be supported by all filesystem-
84 specific fsck implementations.
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87 -y | Y
88 Assume a yes response to all questions asked by fsck.
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91 -o specific-options
92 These specific-options can be any combination of the following
93 separated by commas (with no intervening spaces).
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95 b=n
96 Use block n as the super block for the file system. Block 32 is
97 always one of the alternate super blocks. Determine the
98 location of other super blocks by running newfs(1M) with the -Nv
99 options specified.
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102 c
103 If the file system is in the old (static table) format, convert
104 it to the new (dynamic table) format. If the file system is in
105 the new format, convert it to the old format provided the old
106 format can support the file system configuration. In
107 interactive mode, fsck will list the direction the conversion
108 is to be made and ask whether the conversion should be done. If
109 a negative answer is given, no further operations are done on
110 the file system. In preen mode, the direction of the conversion
111 is listed and done if possible without user interaction.
112 Conversion in preen mode is best used when all the file systems
113 are being converted at once. The format of a file system can be
114 determined from the first line of output from fstyp(1M). Note:
115 the c option is seldom used and is included only for
116 compatibility with pre-4.1 releases. There is no guarantee that
117 this option will be included in future releases.
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120 f
121 Force checking of file systems regardless of the state of their
122 super block clean flag.
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125 p
126 Check and fix the file system non-interactively ("preen"). Exit
127 immediately if there is a problem requiring intervention. This
128 option is required to enable parallel file system checking.
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131 w
132 Check writable file systems only.
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136 EXIT STATUS
137 0
138 file system is unmounted and OK
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141 1
142 erroneous parameters are specified
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145 32
146 file system is unmounted and needs checking (fsck -m only)
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149 33
150 file system is already mounted
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153 34
154 cannot stat device
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157 35
158 a filesystem that is mounted read/write was modified - reboot
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161 36
162 uncorrectable errors detected - terminate normally
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165 37
166 a signal was caught during processing
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169 39
170 uncorrectable errors detected - terminate immediately
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173 40
174 file system is mounted read-only and is OK
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176
177 USAGE
178 The fsck command is large file aware for UFS file systems, per the
179 largefile(5) man page.
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181 FILES
182 /etc/default/fs
183 default local file system type. Default values can be set for the
184 following flags in /etc/default/fs. For example: LOCAL=ufs.
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186 LOCAL
187 The default partition for a command if no FSType is specified.
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191 /etc/vfstab
192 list of default parameters for each file system
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195 ATTRIBUTES
196 See attributes(5) for descriptions of the following attributes:
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201 +--------------------+-----------------+
202 | ATTRIBUTE TYPE | ATTRIBUTE VALUE |
203 +--------------------+-----------------+
204 |Interface Stability | Committed |
205 +--------------------+-----------------+
206
207 SEE ALSO
208 clri(1M), fsck_ufs(1M), fsdb_ufs(1M), fsirand(1M), fstyp(1M), mkfs(1M),
209 mkfs_ufs(1M), mountall(1M), newfs(1M), reboot( 1M), vfstab(4),
210 attributes(5), largefile(5), ufs(7FS)
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212 WARNINGS
213 The operating system buffers file system data. Running fsck on a
214 mounted file system can cause the operating system's buffers to become
215 out of date with respect to the disk. For this reason, the file system
216 should be unmounted when fsck is used. If this is not possible, care
217 should be taken that the system is quiescent and that it is rebooted
218 immediately after fsck is run. Quite often, however, this will not be
219 sufficient. A panic will probably occur if running fsck on a file
220 system modifies the file system.
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222 NOTES
223 This command may not be supported for all FSTypes.
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225
226 Starting with Solaris 9, fsck manages extended attribute data on the
227 disk. (See fsattr(5) for a description of extended file attributes.) A
228 file system with extended attributes can be mounted on versions of
229 Solaris that are not attribute-aware (versions prior to Solaris 9), but
230 the attributes will not be accessible and fsck will strip them from the
231 files and place them in lost+found. Once the attributes have been
232 stripped, the file system is completely stable on versions of Solaris
233 that are not attribute-aware, but would be considered corrupted on
234 attribute-aware versions. In the latter circumstance, run the attribute-
235 aware fsck to stabilize the file system before using it in an
236 attribute-aware environment.
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240 September 8, 2015 FSCK(1M)