projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| ab7d1648 KT |
1 | .TH ICHECK 1M |
| 2 | .SH NAME | |
| 3 | icheck \- file system storage consistency check | |
| 4 | .SH SYNOPSIS | |
| 5 | .B icheck | |
| 6 | [ | |
| 7 | .B \-s | |
| 8 | ] [ | |
| 9 | .B \-b | |
| 10 | numbers ] | |
| 11 | [ filesystem ] | |
| 12 | .SH DESCRIPTION | |
| 13 | .I Icheck | |
| 14 | examines a file system, | |
| 15 | builds a bit map of used blocks, | |
| 16 | and compares this bit map against | |
| 17 | the free list maintained on the file system. | |
| 18 | If the file system is not specified, | |
| 19 | a set of default file systems | |
| 20 | is checked. | |
| 21 | The normal output of | |
| 22 | .I icheck | |
| 23 | includes a report of | |
| 24 | .IP "" | |
| 25 | The total number of files and the numbers of | |
| 26 | regular, directory, block special and character special files. | |
| 27 | .IP "" | |
| 28 | The total number of blocks in use and the numbers of | |
| 29 | single-, double-, and triple-indirect blocks and directory blocks. | |
| 30 | .IP "" | |
| 31 | The number of free blocks. | |
| 32 | .IP "" | |
| 33 | The number of blocks missing; i.e. not in any file | |
| 34 | nor in the free list. | |
| 35 | .PP | |
| 36 | The | |
| 37 | .B \-s | |
| 38 | option causes | |
| 39 | .I icheck | |
| 40 | to ignore the actual free list and reconstruct a new one | |
| 41 | by rewriting the super-block of the file system. | |
| 42 | The file system should be dismounted while this is done; | |
| 43 | if this is not possible (for example if | |
| 44 | the root file system has to be salvaged) | |
| 45 | care should be taken that the system is quiescent and that | |
| 46 | it is rebooted immediately afterwards so that the old, bad in-core | |
| 47 | copy of the super-block will not continue to be used. | |
| 48 | Notice also that | |
| 49 | the words in the super-block | |
| 50 | which indicate the size of the free list and of the | |
| 51 | i-list are believed. | |
| 52 | If the super-block has been curdled | |
| 53 | these words will have to be patched. | |
| 54 | The | |
| 55 | .B \-s | |
| 56 | option | |
| 57 | causes the normal output reports to be suppressed. | |
| 58 | .PP | |
| 59 | Following the | |
| 60 | .B \-b | |
| 61 | option is a list of block numbers; | |
| 62 | whenever any of the named blocks turns up in a file, | |
| 63 | a diagnostic is produced. | |
| 64 | .PP | |
| 65 | .I Icheck | |
| 66 | is faster if the raw version of the special file is used, | |
| 67 | since it reads the i-list many blocks at a time. | |
| 68 | .SH FILES | |
| 69 | Default file systems vary with installation. | |
| 70 | .SH "SEE ALSO" | |
| 71 | dcheck(1), ncheck(1), | |
| 72 | filsys(5), clri(1) | |
| 73 | .SH DIAGNOSTICS | |
| 74 | For duplicate blocks | |
| 75 | and bad blocks (which lie outside the file system) | |
| 76 | .I icheck | |
| 77 | announces the difficulty, the i-number, and the kind of block involved. | |
| 78 | If a read error is encountered, | |
| 79 | the block number of the bad block is printed and | |
| 80 | .I icheck | |
| 81 | considers it to contain 0. | |
| 82 | `Bad freeblock' means that | |
| 83 | a block number outside the available space was encountered in the free list. | |
| 84 | `\fIn\fR dups in free' | |
| 85 | means that | |
| 86 | .IR n "" | |
| 87 | blocks were found in the free list which | |
| 88 | duplicate blocks either in some file or in the earlier part of the free list. | |
| 89 | .SH BUGS | |
| 90 | Since | |
| 91 | .I icheck | |
| 92 | is inherently two-pass in nature, extraneous diagnostics | |
| 93 | may be produced if applied to active file systems. | |
| 94 | .br | |
| 95 | It believes even preposterous super-blocks and | |
| 96 | consequently can get core images. |