Visit Our UNIX and Linux User Community

Linux and UNIX Man Pages

Test Your Knowledge in Computers #425
Difficulty: Medium
C# 1.0 was first released in December 2002.
True or False?
Linux & Unix Commands - Search Man Pages

icheck(8) [bsd man page]

ICHECK(8)						      System Manager's Manual							 ICHECK(8)

icheck - file system storage consistency check SYNOPSIS
icheck [ -s ] [ -b numbers ] [ filesystem ] DESCRIPTION
Icheck examines a file system, builds a bit map of used blocks, and compares this bit map against the free list maintained on the file sys- tem. If the file system is not specified, a set of default file systems is checked. The normal output of icheck includes a report of The total number of files and the numbers of regular, directory, block special and character special files, quota nodes, and sym- bolic links. The total number of blocks in use and the numbers of single-, double-, and triple-indirect blocks and directory blocks. The number of free blocks. The number of blocks missing; i.e. not in any file nor in the free list. The -s option causes icheck to ignore the actual free list and reconstruct a new one by rewriting the super-block of the file system. The file system should be dismounted while this is done; if this is not possible (for example if the root file system has to be salvaged) care should be taken that the system is quiescent and that it is rebooted immediately afterwards so that the old, bad in-core copy of the super- block will not continue to be used. Notice also that the words in the super-block which indicate the size of the free list and of the i- list are believed. If the super-block has been curdled these words will have to be patched. The -s option causes the normal output reports to be suppressed. Following the -b option is a list of block numbers; whenever any of the named blocks turns up in a file, a diagnostic is produced. Icheck is faster if the raw version of the special file is used, since it reads the i-list many blocks at a time. SEE ALSO
filsys(5), clri(8), dcheck(8), fsck(8), ncheck(8) DIAGNOSTICS
For duplicate blocks and bad blocks (which lie outside the file system) icheck announces the difficulty, the i-number, and the kind of block involved. If a read error is encountered, the block number of the bad block is printed and icheck considers it to contain 0. `Bad freeblock' means that a block number outside the available space was encountered in the free list. `n dups in free' means that n blocks were found in the free list which duplicate blocks either in some file or in the earlier part of the free list. BUGS
Since icheck is inherently two-pass in nature, extraneous diagnostics may be produced if applied to active file systems. Since default file systems vary with installations, icheck should use fstab(5). It believes even preposterous super-blocks and consequently can get core images. 3rd Berkeley Distribution ICHECK(8)

Check Out this Related Man Page

df_vxfs(1M)															       df_vxfs(1M)

df_vxfs: df - report number of free disk blocks on a VxFS file system SYNOPSIS
[special|directory]... DESCRIPTION
prints the number of free blocks and free inodes in VxFS file systems or directories based on the counts kept in the super-blocks. VxFS dynamically allocates inodes from a pool of free blocks. The number of free inodes and blocks reported by is an estimate based on the number of free 8K or larger extents and the current ratio of allocated inodes to allocated blocks. (Extents smaller than 8K may not be usable for all types of allocation, so does not count free blocks in extents smaller than 8K.) Allocating additional blocks may therefore decrease the count of free inodes and vice versa. If the operand to is a special device name, the file system can be an unmounted or mounted file system (for example, If you specify a directoryname, displays information for the file system at that mount point. If neither special nor directory is specified, the free space on all of the mounted file systems is printed. Options recognizes the following options: Report only the number of kilobytes free. Report the number of files free. Report only an actual count of the blocks in the free list (free inodes are not reported). When this option is specified, reports on raw devices. Specify the file system type Report the entire statvfs(2) structure. Report the total number of inodes, the number of free inodes, number of used inodes and the percentage of inodes in use. Report the allocation in kilobytes. Report on local file systems only. Report the file system name. If invoked with no other options this option prints a list of mounted file system types. Print the number of free extents of each size. Free extents are always an integral power of two in length, ranging from a minimum of one block to the maximum extent size supported by the file system. Report the total allocated block figures and the number of free blocks. Report the percentage of blocks used, the number of blocks used and the number of blocks free. This option cannot be used with other options. Echo the completed command line, but performs no other action. The command line is generated by incorporating the user-specified options and other information derived from This option allows the user to verify the command line. There are a number of options that specify output formats, some combinations of which are incompatible. If an incompatible combination is specified, one of the options will override the other(s). Operands recognizes the following operands: directory Name of the mount point from which the VxFS file system is accessed. special Device name, which contains a mounted or unmounted VxFS file system. EXAMPLES
Report the number of free disk blocks for all mounted file systems: Report the number of free extents of each size, for all mounted VxFS file systems: Report the number of free files for all mounted VxFS file systems: Report the total allocated block figures and the number of free blocks, for all mounted file systems: Report the total allocated block figures and the number of free blocks, for the file system mounted as FILES
File-system devices. File-system devices. Static information about the file systems. mounted-file-system table. SEE ALSO
du(1), df(1M), fsck_vxfs(1M), statvfs(2), fs_vxfs(4), mnttab(4). STANDARDS CONFORMANCE
: SVID2, XPG2, XPG3 df_vxfs(1M)

Featured Tech Videos