Provided by: ocfs2-tools_1.8.6-2ubuntu1_amd64 bug

NAME

       mount.ocfs2 -  mount an OCFS2 filesystem

SYNOPSIS

       mount.ocfs2 [-vn] [-o options] device dir

DESCRIPTION

       mount.ocfs2  mounts  an  OCFS2  filesystem at dir. It is usually invoked indirectly by the
       mount(8) command.

OPTIONS

       _netdev
              Indicates that the file system resides on a device  that  requires  network  access
              (used  to  prevent  the system from attempting to mount these filesystems until the
              network has been enabled on the system). mount.ocfs2(8) transparently appends  this
              option  during  mount.  However,  users  mounting  the  volume  via /etc/fstab must
              explicitly specify this mount option to delay the system from mounting  the  volume
              until after the network has been enabled.

       noatime
              The file system will not update access time.

       relatime
              The  file system will update atime only if the on-disk atime is older than mtime or
              ctime.

       strictatime,atime_quantum=nrsec
              The file system will always perform atime updates, but the minimum update  interval
              is  specified  by atime_quantum which defaults to 60 secs. Set it to zero to always
              update atime. These two options need work together.

       [no]acl
              Enables / disables POSIX ACLs (access control lists) support.

       [no]user_xattr
              Enables / disables extended user attributes.

       commit=nrsec
              Sync all data and metadata every nrsec seconds. The default  value  is  5  seconds.
              Zero means default.

       data=[ordered|writeback]
              Specifies the handling of file data during metadata journalling.

              ordered
                     This  is  the default mode. Data is flushed to disk before the corresponding
                     meta-data is committed to the journal.

              writeback
                     Data  ordering is not preserved - data may be  flushed  to  disk  after  the
                     corresponding  meta-data  is committed to the journal. This is rumored to be
                     the higher-throughput option.  While  it  guarantees  internal  file  system
                     integrity,  it  can  allow  old  data  to  appear in files after a crash and
                     journal recovery.

       errors=[remount-ro|errors=panic|errors=continue]
              Specifies the behavior when an on-disk corruption is encountered.

              remount-ro
                     This is the default mode. The file system is remounted read-only.

              panic  The system is halted via panic.

              continue
                     Ignore errors. Just log error message, return  error  code  to  the  calling
                     process and continue.

       localflocks
              This disables cluster-aware flock(2).

       coherency=[full|coherency]
              Specifies  the  extent  of  coherency  for the cached file data across the cluster.
              This mount option works with Linux kernel 2.6.37 and later.

              full   This is the default mode. The file system ensures the cached  file  data  is
                     coherent across the cluster for all IO modes.

              buffered
                     The  file  system  only  ensures the cached file data coherency for buffered
                     mode IOs.  It does not perform IO serialization for direct IOs. This  allows
                     multiple  nodes  to  perform concurrent direct IOs to the same file. This is
                     the recommended mode for volumes hosting database files.

       resv_level=level
              Specifies the level of allocation reservation for files. The higher the value,  the
              more  aggressive  it is. Valid values are between 0 (reservation off) to 8 (maximum
              space for reservation). It defaults to 2. This mount option works with Linux kernel
              2.6.35 and later.

       dir_resv_level=level
              By  default,  directory  reservation  scales  with file reserveration. Users should
              rarely need to change this value. If the file allocation reservation is turned off,
              this  option  will have no effect. This mount option works with Linux kernel 2.6.35
              and later.

       inode64
              Indicates that the file system can create inodes at any  location  in  the  volume,
              including those which will result in inode numbers greater than 4 billion.

       [no]intr
              Specifies whether a signal can interrupt IOs. It is disabled by default.

       ro     Mount the file system read-only.

       rw     Mount the file system read-write.

NOTES

       To mount and umount a OCFS2 volume, do:

       # mount /dev/sda1 /mount/path
        ...
       # umount /mount/path

       Users mounting a clustered volume should be aware of the following:

           1. The cluster stack must to be online for a clustered mount to succeed.

           2.  The  clustered  mount operation is not instantaneous; it must wait for the node to
           join the DLM domain.

           3. Likewise, clustered umount is also not instantaneous;  it  involves  migrating  all
           mastered lock-resources to the other nodes in the cluster.

       If  the  mount  fails,  detailed  errors  can  be  found via dmesg(8). These might include
       incorrect cluster configuration (say, a  missing  node  or  incorrect  IP  address)  or  a
       firewall  interfering  with  o2cb  network  traffic.  Check the configuration as listed in
       o2cb(7) or the man page of the active cluster stack.

       To auto-mount volumes on startup, the file system tools include  an  ocfs2  init  service.
       This  runs  after  the  o2cb  init service has started the cluster. The ocfs2 init service
       mounts all OCFS2 volumes listed in /etc/fstab.

       # chkconfig --add o2cb
       o2cb 0:off 1:off 2:on 3:on 4:off 5:on 6:off

       $ chkconfig --add ocfs2
       o2cb 0:off 1:off 2:on 3:on 4:off 5:on 6:off

       $ cat /etc/fstab
        ...
       /dev/sda1     /u01     ocfs2     _netdev,defaults     0  0
        ...

SEE ALSO

       debugfs.ocfs2(8)  fsck.ocfs2(8)  mkfs.ocfs2(8)   mounted.ocfs2(8)   o2cb(7)   o2cluster(8)
       o2image(8) o2info(1) tunefs.ocfs2(8)

AUTHORS

       Oracle Corporation

COPYRIGHT

       Copyright © 2004, 2012 Oracle. All rights reserved.