1 2 3 4FSCK(8) 1991 FSCK(8) 5 6 7NNAAMMEE 8 fsck - file system consistency check and interactive 9 repair 10 11SSYYNNOOPPSSIISS 12 ffsscckk --pp [ --mm mode ] 13 ffsscckk [ --bb block# ] [ --cc ] [ --yy ] [ --nn ] [ --mm mode ] [ 14 filesystem ] ... 15 16DDEESSCCRRIIPPTTIIOONN 17 The first form of _f_s_c_k preens a standard set of 18 filesystems or the specified file systems. It is normally 19 used in the script //eettcc//rrcc during automatic reboot. Here 20 _f_s_c_k reads the table //eettcc//ffssttaabb to determine which file 21 systems to check. Only partitions in fstab that are 22 mounted ``rw,'' ``rq'' or ``ro'' and that have non-zero 23 pass number are checked. Filesystems with pass number 1 24 (normally just the root filesystem) are checked one at a 25 time. When pass 1 completes, all remaining filesystems 26 are checked, running one process per disk drive. The disk 27 drive containing each filesystem is inferred from the 28 longest prefix of the device name that ends in a digit; 29 the remaining characters are assumed to be the partition 30 designator. 31 32 The system takes care that only a restricted class of 33 innocuous inconsistencies can happen unless hardware or 34 software failures intervene. These are limited to the 35 following: 36 37 Unreferenced inodes 38 39 Link counts in inodes too large 40 41 Missing blocks in the free map 42 43 Blocks in the free map also in files 44 45 Counts in the super-block wrong 46 47 These are the only inconsistencies that _f_s_c_k with the --pp 48 option will correct; if it encounters other 49 inconsistencies, it exits with an abnormal return status 50 and an automatic reboot will then fail. For each 51 corrected inconsistency one or more lines will be printed 52 identifying the file system on which the correction will 53 take place, and the nature of the correction. After 54 successfully correcting a file system, _f_s_c_k will print the 55 number of files on that file system, the number of used 56 and free blocks, and the percentage of fragmentation. 57 58 If sent a QUIT signal, _f_s_c_k will finish the file system 59 checks, then exit with an abnormal return status that 60 causes an automatic reboot to fail. This is useful when 61 62 63 6420, April 1 65 66 67 68 69 70FSCK(8) 1991 FSCK(8) 71 72 73 to finish the file system checks during an automatic 74 reboot, but do not want the machine to come up multiuser 75 after the checks complete. 76 77 Without the --pp option, _f_s_c_k audits and interactively 78 repairs inconsistent conditions for file systems. If the 79 file system is inconsistent the operator is prompted for 80 concurrence before each correction is attempted. It 81 should be noted that some of the corrective actions which 82 are not correctable under the --pp option will result in 83 some loss of data. The amount and severity of data lost 84 may be determined from the diagnostic output. The default 85 action for each consistency correction is to wait for the 86 operator to respond yyeess or nnoo. If the operator does not 87 have write permission on the file system _f_s_c_k will default 88 to a --nn action. 89 90 _F_s_c_k has more consistency checks than its predecessors 91 _c_h_e_c_k, _d_c_h_e_c_k, _f_c_h_e_c_k, and _i_c_h_e_c_k combined. 92 93 The following flags are interpreted by _f_s_c_k. 94 95 --bb Use the block specified immediately after the flag 96 as the super block for the file system. Block 32 is 97 usually an alternate super block. 98 99 --ll Limit the number of parallel checks to the number 100 specified in the following argument. By default, 101 the limit is the number of disks, running one 102 process per disk. If a smaller limit is given, the 103 disks are checked round-robin, one filesystem at a 104 time. 105 106 --mm Use the mode specified in octal immediately after 107 the flag as the permission bits to use when creating 108 the lost+found directory rather than the default 109 1777. In particular, systems that do not wish to 110 have lost files accessible by all users on the 111 system should use a more restrictive set of 112 permissions such as 700. 113 114 --yy Assume a yes response to all questions asked by 115 _f_s_c_k; this should be used with great caution as this 116 is a free license to continue after essentially 117 unlimited trouble has been encountered. 118 119 --nn Assume a no response to all questions asked by _f_s_c_k 120 except for ``CONTINUE?'', which is assumed to be 121 affirmative; do not open the file system for 122 writing. 123 124 --cc If the file system is in the old (static table) 125 format, convert it to the new (dynamic table) 126 format. If the file system is in the new format, 127 128 129 13020, April 2 131 132 133 134 135 136FSCK(8) 1991 FSCK(8) 137 138 139 convert it to the old format provided the old format 140 can support the filesystem configuration. In 141 interactive mode, _f_s_c_k will list the direction the 142 conversion is to be made and ask whether the 143 conversion should be done. If a negative answer is 144 given, no further operations are done on the 145 filesystem. In preen mode, the direction of the 146 conversion is listed and done if possible without 147 user interaction. Conversion in preen mode is best 148 used when all the file systems are being converted 149 at once. The format of a file system can be 150 determined from the first line of output from 151 _d_u_m_p_f_s(8). 152 153 If no filesystems are given to _f_s_c_k then a default list of 154 file systems is read from the file //eettcc//ffssttaabb. 155 156 Inconsistencies checked are as follows: 157 158 1. Blocks claimed by more than one inode or the free 159 map. 160 2. Blocks claimed by an inode outside the range of the 161 file system. 162 3. Incorrect link counts. 163 4. Size checks: 164 Directory size not of proper format. 165 Partially truncated file. 166 5. Bad inode format. 167 6. Blocks not accounted for anywhere. 168 7. Directory checks: 169 File pointing to unallocated inode. 170 Inode number out of range. 171 Dot or dot-dot not the first two entries of a 172 directory or having the wrong inode number. 173 8. Super Block checks: 174 More blocks for inodes than there are in the 175 file system. 176 9. Bad free block map format. 177 10. Total free block and/or free inode count incorrect. 178 179 Orphaned files and directories (allocated but 180 unreferenced) are, with the operator's concurrence, 181 reconnected by placing them in the lloosstt++ffoouunndd directory. 182 The name assigned is the inode number. If the _l_o_s_t+_f_o_u_n_d 183 directory does not exist, it is created. If there is 184 insufficient space its size is increased. 185 186 Because of inconsistencies between the block device and 187 the buffer cache, the raw device should always be used. 188 189FFIILLEESS 190 /etc/fstab contains default list of file systems 191 to check. 192 193 194 195 19620, April 3 197 198 199 200 201 202FSCK(8) 1991 FSCK(8) 203 204 205DDIIAAGGNNOOSSTTIICCSS 206 The diagnostics produced by _f_s_c_k are fully enumerated and 207 explained in Appendix A of ``Fsck - The UNIX File System 208 Check Program'' (SMM:5). 209 210SSEEEE AALLSSOO 211 fstab(5), fs(5), fsdb(8), newfs(8), mkfs(8), reboot(8) 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 26220, April 4 263 264 265