fsck_vxfs(1M)															     fsck_vxfs(1M)

NAME

       fsck_vxfs: fsck - check and repair a VxFS file system

SYNOPSIS

       [special ... ]

       [special ... ]

DESCRIPTION

       checks  VxFS file systems for consistency.  Because VxFS records pending file system updates in an intent log, typically replays the intent
       log instead of doing a full structural file system check.  You can use options to force a full structural file system check.

       special specifies one or more special character devices (for example, or

       If multiple devices are specified, each device is checked in turn unless the option or the suboption is also specified, in which  case  the
       devices	are  checked in parallel.  If special is not specified, prompts you with each file system listed in to determine which file system
       to check, unless you specify or to automatically answer yes to the prompts.

   Options
       recognizes the following options:

       Specify the VxFS file system type.

       Check whether or not the file system is marked clean.
		      This option does not validate the file system.  The file system could have been corrupted since it  was  marked  clean  (for
		      example,	by  a  system  crash), and if so, a mount could fail.  In that case, a full would be required to clean it.  Use to
		      test for file system corruption.

       Assume a "no" response to all prompts by
		      do not open the file system for writing, do not replay the intent log.  A full file system check is performed.

       Specify VxFS file system specific options. See "The -o Specific Options"
		      topic in this section.

       Produce messages that identify the device being checked.

       With VxFS,     is used by by default; it does not provide any functionality.

       Safe performance mode.  To improve performance, a system wide
		      will not be issued.

       Echo the completed command line, but do not execute the command.
		      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.

       Assume a "yes" response to all prompts by
		      Additionally,  if the file system requires a full file system check after the log replay, or if the suboption causes the log
		      replay to be skipped and the file system is not clean, then a full file system check is performed.

       Because VxFS maintains an intent log, a complete check is generally not required; the default is to replay the intent log only.	If detects
       file  system  damage  or  the  log replay operation detects damage, an indication that a complete check is required is placed in the super-
       block.  In this case, if the option was specified, the full check will be run after the log replay.  If the option was not  used,  must	be
       run again, with the option to perform the full structural check.

   Operands
       recognizes the following operand:

       special	      Name of one or more special character devices which contain VxFS file systems.

   The -o Specific Options
       The option specifies VxFS file system specific options.	These options can be a combination of the following in a comma-separated list:

       Perform a full file system check.

       Allows a full check of a mounted file system.
		      is  only	used  internally  as  part of the primary cluster node recovery process after the primary fails.  Never enter this
		      option from the command line as it can destroy a file system if not used correctly.

       Do not perform log replay.  This option may be used if the log area
		      was physically damaged.

		      Note: Use the option to verify whether there are file system inconsistencies.  Use to fix a corrupted file system and  avoid
		      a log replay.  If you run without on a clean file system, it replays the intent log and performs a full file system check.

       Allows parallel log replay for several VxFS file systems.
		      Each message from is prefixed with the device name to identify the device.  This suboption does not perform a full file sys-
		      tem check in parallel; that is still done sequentially on each device, even  when  multiple  devices  are  specified.   This
		      option  is  compatible only with the option (that is, non-interactive full file system check), in which case a log replay is
		      done in parallel on all specified devices.  A sequential full file system check is performed on devices where  needed.   The
		      number  of  devices  that  can  be  checked  in  parallel is determined by the amount of physical memory in the system.  One
		      instance of on a single device can consume up to a maximum of 32 megabytes of memory.

   Check a File System
       A full check looks for the following inconsistencies:

	      o  Blocks claimed by more than one inode or the free list.
	      o  Blocks claimed by an inode outside the range of the file system.
	      o  Incorrect link counts.
	      o  Size checks:
		      -  Incorrect number of blocks.
		      -  Directory entry format.
	      o  Bad inode format.
	      o  Blocks not accounted for anywhere.
	      o  Directory checks:
		      -  File pointing to unallocated inode.
		      -  Inode number out of range.
		      -  Linkage to parent directory.
		      -  Hash chain linkage.
		      -  Free space count.
	      o  Super-block checks:
		      -  Checksum mismatch.
		      -  More blocks for inodes than there are in the file system.
	      o  Structural Files:
		      -  Fileset headers.
		      -  Object Location Table (OLT).
		      -  Inode list files.
		      -  Inode allocation summary files.
		      -  Attribute files (including Access Control Lists).
		      -  Attribute link counts.
	      o  Bad free block list format.
	      o  Total free block and/or free inode count incorrect.

   Lost and Found Directory
       Orphaned files and directories (allocated but unreferenced) are, with the user's agreement, reconnected by placing them in  the	directory.
       The name assigned is the inode number.  The only restriction is that the directory must already exist in the file system's root directory.

   Notes
       Checking the raw device is almost always faster.

       Unlike 2.x and earlier releases of VxFS, a full file system check does not always perform pending extended inode operations.  Some extended
       operations can only be processed when the file system is mounted.  A file system that has been marked can  still  contain  extended  opera-
       tions.

       If a structural flaw is detected during the intent log replay, the full flag is set on the file system without operator interaction.

       If fsck encounters a large file on an older OS version, the command stops without completing the file system check.

RETURN VALUES

       Structural  errors  discovered  during a full check are displayed on standard output.  Responses required during a full check are read from
       standard input.

       The following return codes are used for the option for all devices other than the one used by the root file system:

	      The file system is unmounted and clean.

	      The open of the device file failed.

	      The file system is unmounted and needs checking.

	      The file system is mounted.

	      The stat of the device failed.

	      Other   The state could not be determined because of an error.

       The following return codes are used for the option for the device used by the root file system:

	      The root file system is mounted read-only and is clean, or
		      the root file system is mounted read/write and therefore is clean.

	      The root file system is mounted read-only and needs checking.

	      The stat of the device failed.

	      Other   The state could not be determined because of an error.

       In most cases, prints the following messages:

       If the file system is already clean, prints the following message instead:

       If prints any other messages, a full structural check is needed.  If the option is specified, performs (if necessary) a	full  check  after
       running the intent log replay. If the option is not used, must be invoked with the option to perform a full structural check.

       If or is specified, prints the following messages for a device, for example

DIAGNOSTICS

       All  error  messages  that  relate to the contents of a file system produced during a log replay are displayed on standard output.  All I/O
       failures and exit messages are displayed on standard error output.

WARNINGS

       allows a full check of a mounted file system.  is only used internally as part of the primary cluster node recovery process after the  pri-
       mary fails.  Never enter this option from the command line as it can destroy a file system if not used correctly.

SEE ALSO

       fsck(1M), fsck_hfs(1M), mkfs(1M), mkfs_vxfs(1M), ncheck_vxfs(1M), fs_vxfs(4).

																     fsck_vxfs(1M)