HP-UX Reference (11i v1 05/09) - 1M System Administration Commands A-M (vol 3)

f
fsdb_vxfs(1M) fsdb_vxfs(1M)
NAME
fsdb - VxFS file system debugger
SYNOPSIS
/usr/sbin/fsdb
[-F vxfs][-z inumber] special
DESCRIPTION
fsdb can analyze VxFS file system problems or repair a damaged VxFS file system after a crash. A special
device special specifies the file system to debug. The
fsdb command is intended for experienced users
only.
fsdb can convert block and inumbers into their corresponding disk addresses. In addition, mnemonic
offsets allow access to different parts of an inode. These greatly simplify the process of correcting control
block entries or descending the file system tree.
By default, numbers are considered decimal. You must prefix octal numbers with
0, and prefix hexade-
cimal numbers with
0x. When using hexadecimal numbers, it is preferable to follow the number with a
space, because several commands are letters that are also hexadecimal digits. In this document a pound
sign (#) indicates that a number is to be specified.
fsdb reads a block at a time and works with raw and block I/O. All I/O is unbuffered, so changes made to
the file system are immediate and changes made by other processes or by the kernel are immediately seen
by fsdb.
Options
-F vxfs Specify the VxFS file-system type.
-z inumber Clear the inode identified by inumber (non-interactive). Multiple
-z options accumu-
late.
The following symbols are recognized by the
fsdb command:
h[mod|print]
Print summary of commands that display [modify|format] the file system.
?[mod|print]
Print summary of commands that display [modify|format] the file system.
help[mod|print]
Print summary of commands that display [modify|format] the file system.
! Escape to shell.
| Pipe output of fsdb to a shell command.
q Quit.
string A character string. Inside a character string, a NULL character may be specified with
‘‘\0’’; a double quote may be specified with ‘‘\"’’; and a backslash may be specified with
‘‘\\ ’’.
+-∗ /% Add, subtract, multiply, divide, and modulus.
= Assignment
i An inode in the primary inode list.
ai An inode in the attribute inode list.
au An allocation unit.
b Ablock.
im The immediate data area of an inode. Small directories and symbolic link files (96
bytes or less) are stored directly in the inode itself, in the area normally occupied by
data block numbers and extent sizes.
attr An attribute inode.
cdb Current directory block.
d A directory entry.
HP-UX 11i Version 1: September 2005 − 1 − Hewlett-Packard Company Section 1M−−271