NAME

fsdb − examine/modify file system

SYNOPSIS

fsdb file-system

HP-UX COMPATIBILITY

Level: HP-UX/NON-STANDARD

Origin: HP

Remarks: This manual entry describes fsdb as implemented on the Series 500 computers.  Refer to other fsdb(1M) entries for information valid for other implementations.  Note that fsdb on the Series 500 is an experimental utility which could change in future releases. 

DESCRIPTION

Fsdb provides you with the ability to perform the following functions for each specified SDF file-system:

1.  Find the inode number of a file, given its full path name.  The file-system must be the root file system, or must be mountable to use this feature. 

2.  Examine and modify the  contents  of  the  superblock  (volume header). 

3.  Examine and modify the  contents  of any  inode or other  file attribute file record. 

Integer  input to fsdb may be entered in decimal  (default), octal (with a preceding "0"), or hexadecimal (with a preceding "0x"). 

File-system is a raw or block special file describing the device on which the file system is located. 

Fsdb may be executed only by the super-user. 

Fsdb execution is largely self-explanatory.  Prompts consist of questions requesting the needed information.  When execution begins, fsdb displays the following menu:

1 − find inode numbers.
2 − examine superblock.
3 − examine inodes.
q − quit.

after which you are requested to enter one of the options shown.  Typing 1 causes fsdb to accept full pathnames of files, in return for which it prints the corresponding inode number.  Typing q returns you to the main menu. 

Typing 2 displays the contents of each record in the superblock.  Each record is numbered.  If a right parenthesis ")" follows the number, then the record can be modified.  If a right curly bracket "}" follows the number, then the record cannot be modified.  You are then asked whether or not you want to modify the superblock.  An answer beginning with n sends you back to the menu; an initial y causes fsdb to ask for the record number to be modified.  If the record number specified cannot be modified, you are told about it, and prompted for another record number.  If you specify a record number which can be changed, you are prompted for the new data.  Typing q returns you to the main menu. 

Typing 3 causes fsdb to prompt you for a file attribute record number.  Upon receipt of a valid number, the contents of that record are displayed, and you are prompted for the information you want to change.  Parentheses and curly brackets have the same meanings as described above.  Typing q returns you to the main menu. 

Typing q at the main menu level terminates the command. 

A word of caution:  fsdb is deceptively easy to use, and therefore should be used with extreme care.  Be sure you know what you are doing before you enter too deeply into options 2 or 3.  You are given the opportunity to abort (by typing q) any operation before you have changed anything, so consider carefully what you are about to do before you do it.  Fsdb does not provide an "undo" function − the changes you make are immediate. 

SEE ALSO

fsck(1M). 

BUGS

If fsdb changes a field that is  duplicated in an in-memory OS data  structure, the change may be undone by the OS.  Forcing a reboot while still in fsdb sometimes  circumnavigates this  problem.  Changes  to  inodes 0 and 1 always  fall into this category. 

Hewlett-Packard  —  last mod. May 11, 2021