Ubuntu Manpage: mount.ocfs2 - mount an OCFS2 filesystem

Provided by: ocfs2-tools_1.8.7-1build4_amd64

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. This is
the default mode.

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. It is enabled by default.

[no]user_xattr
Enables / disables extended user attributes. It is enabled by default.

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.

nocluster
This option allows users to mount a clustered volume without configuring the cluster stack.
However, you must be aware that you can only mount the file system from one node at the same time,
otherwise, the file system may be damaged. Please use it with caution.

[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
        ...

AUTHORS

       Oracle Corporation

COPYRIGHT

       Copyright © 2004, 2012 Oracle. All rights reserved.

Version 1.8.7                                     January 2012                                    mount.ocfs2(8)