mount_ufs - mount ufs file systems


     mount -F ufs  [generic_options]  [-o specific_options]  [-O]
     special | mount_point

     mount -F ufs  [generic_options]  [-o specific_options]  [-O]
     special mount_point


     The mount utility attaches a ufs file  system  to  the  file
     system  hierarchy  at the mount_point, which is the pathname
     of a directory. If mount_point has any contents prior to the
     mount  operation,  these are hidden until the file system is

     If mount is invoked with special or mount_point as the  only
     arguments,  mount  will  search  /etc/vfstab  to fill in the
     missing  arguments,  including  the  specific_options.   See

     If  special  and  mount_point  are  specified  without   any
     specific_options, the default is rw.

     If the directory on which a file system is to be mounted  is
     a symbolic link, the file system is mounted on the directory
     to which the symbolic link refers, rather than on top of the
     symbolic link itself.


     See mount(1M) for the list of supported generic_options.

     The following options are supported:

          -o specific_options
                Specify ufs file system  specific  options  in  a
                comma-separated  list with no intervening spaces.
                If invalid options are specified, a warning  mes-
                sage  is  printed  and  the  invalid  options are
                ignored. The following options are available:

                dfratime | nodfratime
                      By default, writing access time updates  to
                      the disk may be deferred (dfratime) for the
                      file system until the disk is accessed  for
                      a  reason other than updating access times.
                      nodfratime disables this behavior.

                      If power management is enabled on the  sys-
                      tem,  do  not set nodfratime unless noatime
                      is also set. If you set nodfratime  without
                      setting  noatime, the disk is spun up every
                      time a file within a  file  system  on  the
                      disk  is accessed - even if the file is not

                forcedirectio | noforcedirectio
                      If forcedirectio is specified and supported
                      by  the  file system, then for the duration
                      of the mount, forced  direct  I/O  will  be
                      used.  If  the  filesystem is mounted using
                      forcedirectio, data is transferred directly
                      between user address space and the disk. If
                      the  filesystem  is  mounted  using  nofor-
                      cedirectio,  data  is  buffered  in  kernel
                      address  space  when  data  is  transferred
                      between  user  address  space and the disk.
                      forcedirectio is a performance option  that
                      is of benefit only in large sequential data
                      transfers. The default behavior  is  nofor-

                global | noglobal
                      If global is specified and supported on the
                      file  system, and the system in question is
                      part of a cluster, the file system will  be
                      globally  visible on all nodes of the clus-
                      ter. If noglobal is  specified,  the  mount
                      will  not  be globally visible. The default
                      behavior is noglobal. The global option  is
                      mutually  exclusive  of  the nbmand option,
                      described below.

                intr | nointr
                      Allow (do not allow) keyboard interrupts to
                      kill  a  process  that  is  waiting  for an
                      operation on  a  locked  file  system.  The
                      default is intr.

                largefiles | nolargefiles
                      If nolargefiles is specified and  supported
                      by  the  file system, then for the duration
                      of the mount it is guaranteed that all reg-
                      ular  files  in the file system have a size
                      that will fit in  the  smallest  object  of
                      type off_t supported by the system perform-
                      ing the mount. The mount will fail if there
                      are  any files in the file system not meet-
                      ing this criterion. If largefiles is speci-
                      fied,  there  is  no  such  guarantee.  The
                      default behavior is largefiles.

                      If nolargefiles is  specified,  mount  will
                      fail  for  ufs  if  the  file  system to be
                      mounted has contained a large file (a  file
                      whose  size  is  greater than or equal to 2
                      Gbyte) since the last invocation of fsck on
                      the  file  system.  The large file need not
                      be present in the file system at  the  time
                      of  the  mount  for  the  mount to fail; it
                      could have been created previously and des-
                      troyed. Invoking fsck (see fsck_ufs(1M)) on
                      the file system will reset the file  system
                      state  if no large files are present. After
                      invoking  fsck, a successful mount  of  the
                      file  system  with  nolargefiles  specified
                      indicates the absence of large files in the
                      file  system; an unsuccessful mount attempt
                      indicates the  presence  of  at  least  one
                      large file.

                logging | nologging
                      If logging is specified,  then  logging  is
                      enabled  for  the  duration  of the mounted
                      file system.  Logging  is  the  process  of
                      storing  transactions (changes that make up
                      a complete UFS operation) in a  log  before
                      the  transactions  are  applied to the file
                      system. Once a transaction is  stored,  the
                      transaction can be applied to the file sys-
                      tem later. This prevents file systems  from
                      becoming  inconsistent, therefore eliminat-
                      ing the need to  run  fsck.   And,  because
                      fsck  can  be bypassed, logging reduces the
                      time required to  reboot  a  system  if  it
                      crashes, or after an unclean halt.

                      The default behavior is logging for all UFS
                      file systems.

                      The log is allocated from  free  blocks  in
                      the file system, and is sized approximately
                      1 Mbyte per 1 Gbyte of file system, up to a
                      maximum of 64 Mbytes.

                      Logging is enabled on any UFS file  system,
                      including  root  (/), except under the fol-
                      lowing conditions:

                         o  When  logging  is  specifically  dis-

                         o  If there is insufficient file  system
                            space  for the log. In this case, the
                            following message  is  displayed  and
                            file system is still mounted:

                            # mount /dev/dsk/c0t4d0s0 /mnt
                              /mnt: No space left on device
                              Could not enable logging for /mnt on  /dev/dsk/c0t4d0s0.

                            The log created  by  UFS  logging  is
                            continually  flushed  as it fills up.
                            The log is totally flushed  when  the
                            file  system  is  unmounted  or  as a
                            result of the lockfs -f command.

                m     Mount the file  system  without  making  an
                      entry in /etc/mnttab.

                nbmand | nonbmand
                      This  option  specifies  that  non-blocking
                      mandatory   locking   semantics  should  be
                      allowed on this file  system.  Non-blocking
                      mandatory locking is disallowed by default.
                      If the file  system  is  mounted  with  the
                      nbmand  option,  then  applications can use
                      the  fcntl(2)  interface  to   place   non-
                      blocking  mandatory  locks on files and the
                      system will enforce those semantics.   Ena-
                      bling  this option can cause standards con-
                      formant  applications  to  see   unexpected

                      Do not use the nbmand option with  /,  /var
                      and /usr.

                      The remount option should not  be  used  to
                      change  the  nbmand disposition of the file
                      system.  The  nbmand  option  is   mutually
                      exclusive  of  the global option, described

                      By default, the file system is mounted with
                      normal  access  time  (atime) recording. If
                      noatime is specified, the file system  will
                      ignore access time updates on files, except
                      when they  coincide  with  updates  to  the
                      ctime  or  mtime.  See stat(2). This option
                      reduces disk activity on file systems where
                      access  times are unimportant (for example,
                      a Usenet news spool).

                      noatime turns  off  access  time  recording
                      regardless of dfratime or nodfratime.
                       The POSIX standard  requires  that  access
                      times  be marked on files. -noatime ignores
                      them unless the file is also modified.

                onerror = action
                      This option specifies the action  that  UFS
                      should  take  to  recover  from an internal
                      inconsistency on  a  file  system.  Specify
                      action  as  panic,  lock,  or umount. These
                      values cause a forced  system  shutdown,  a
                      file  system lock to be applied to the file
                      system, or the file system to  be  forcibly
                      unmounted,  respectively.  The  default  is

                quota Quotas are turned on for the file system.

                      Remounts a file system with a  new  set  of
                      options.  All  options  not  explicitly set
                      with  remount  revert  to   their   default

                rq    Read-write   with   quotas    turned    on.
                      Equivalent to rw, quota.

                ro | rw
                      Read-only or read-write. Default is rw.

                suid | nosuid
                      Allow or disallow setuid/setgid  execution.
                      The  default  is  suid.  This  option  also
                      allows/disallows opening any device-special
                      entries that appear within the filesystem.

                      This option is highly recommended  whenever
                      the  file system is shared via NFS with the
                      root=  option,  because,  without  it,  NFS
                      clients  could  add  setuid programs to the
                      server, or create devices that  could  open
                      security holes.

          -O    Overlay  mount.  Allow  the  file  system  to  be
                mounted  over an existing mount point, making the
                underlying file system inaccessible. If  a  mount
                is   attempted  on  a  pre-existing  mount  point
                without setting this flag, the mount  will  fail,
                producing the error "device busy".

     The mount_ufs command supports the xattr flag, to allow  the
     creation   and  manipulation  of  extended  attributes.  See
     fsattr(5) for a  description  of  extended  attributes.  The
     xattr flag is always on.


     When a UFS file system is mounted with logging enabled, file
     system  transactions  that  free blocks from files might not
     actually add those freed blocks to the  file  system's  free
     list  until  some  unspecified  time  in  the  future.  This
     behavior improves file system performance but does not  con-
     form  to the POSIX, Single UNIX Specification, SPARC Confor-
     mance Definition, System  V  Application  Binary  Interface,
     System  V Interface Definition, and X/Open Portability Guide
     Standards, which  require  that  freed  space  be  available
     immediately.  To enable standards conformance regarding file
     deletions or to address the problem of  not  being  able  to
     grow  files  on a relatively full UFS file system even after
     files have been deleted, disable UFS logging.


           table of mounted file systems

           list of default parameters for each file system


     See attributes(5) for descriptions of the  following  attri-

    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    | Availability                | SUNWcsu                     |


     fsck(1M), fsck_ufs(1M), mount(1M),  mountall(1M),  fcntl(2),
     mount(2),   stat(2),  mnttab(4),  vfstab(4),  attributes(5),
     fsattr(5), largefile(5)


     Since the root (/) file system is mounted read-only  by  the
     kernel during the boot process, only the remount option (and
     options that can be used in conjunction with remount) affect
     the root (/) entry in the /etc/vfstab file.

     File system transactions that free blocks from  files  might
     not  immediately  add  the freed blocks to the file system's
     free list. This behavior occurs in a system that has  a  UFS
     file system mounted with logging enabled.

     This behavior improves file system performance, but does not
     conform to the following standards:

        o   POSIX, Single UNIX Specification

        o   SPARC Conformance Definition

        o   System V Application Binary Interface

        o   System V Interface Definition

        o   X/Open Portability Guide

      These standards  require  that  freed  space  be  available

      Consider disabling UFS logging under the  following  condi-

        o  You want to  enable  standards  conformance  regarding
           file deletions.

        o  You  encounter  problems  creating  or  growing  files
           immediately  after  files have been deleted on a rela-
           tively full file system.

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