mount Command

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Purpose

Makes a file system available for use.

Syntax

mount [ -f ] [ -n node ] [ -o options ] [ -p ] [ -r ] [ -v vfsname ] [ -F AltFSfile ] [ -t type | [ device | node:directory ] directory | all | -a ] [-V [generic_options] special_mount_points ]

Description

The mount command instructs the operating system to make a file system available for use at a specified location (the mount point). In addition, you can use the mount command to build other file trees made up of directory and file mounts. The mount command mounts a file system expressed as a device using the device or node:directory parameter on the directory specified by the directory parameter. After the mount command has finished, the directory specified becomes the root directory of the newly mounted file system.

Only users with root authority or are members of the system group and have write access to the mount point can issue file or directory mounts. The file or directory may be a symbolic link. The mount command uses the real user ID, not the effective user ID, to determine if the user has appropriate access. System group members can issue device mounts, provided they have write access to the mount point and those mounts specified in the /etc/filesystems file. Users with root user authority can issue any mount command.

Users can mount a device provided they belong to the system group and have appropriate access. When mounting a device, the mount command uses the device parameter as the name of the block device and the directory parameter as the directory on which to mount the file system.

If you enter the mount command without flags, the command displays the following information for the mounted file systems:

  • the node (if the mount is remote)
  • the object mounted
  • the mount point
  • the virtual-file-system type
  • the time mounted
  • any mount options

If you specify only the directory or node:directory parameter, the mount command takes it to be the name of the directory or file on which a file system, directory, or file is usually mounted (as defined in the /etc/filesystems file). The mount command looks up the associated device, directory, or file and mounts it. This is the most convenient way of using the mount command, because it does not require you to remember what is normally mounted on a directory or file. You can also specify only the device. In this case, the command obtains the mount point from the /etc/filesystems file.

The /etc/filesystems file should include a stanza for each mountable file system, directory, or file. This stanza should specify at least the name of the file system and either the device on which it resides or the directory name. If the stanza includes a mount attribute, the mount command uses the associated values. It recognizes five values for the mount attributes: automatic, true, false, removable, and readonly.

The mount all command causes all file systems with the mount=true attribute to be mounted in their normal places. This command is typically used during system initialization, and the corresponding mount operations are referred to as automatic mount operations.

By default, the mount command runs the wlmcntrl command to refresh the current assignment rules in the kernel after mounting the file system. In some situations (such as when many file systems are mounted at once, or when a rule for an inaccessible remote mount is present in the workload manager configuration), calling wlmcntrl automatically after mount might be undesirable.

If you wish to override this behavior, set the environment variable MOUNT_WLMCNTRL_SELFMANAGE to any value. This will avoid calling the wlmcntrl command during the mount operation. You must manually run wlmcntrl -u -d "" to refresh the current assignment rules in the kernel. For more information, see wlmcntrl command.

Note:
  1. If the cdromd CD and DVD automount daemon is enabled, those devices will be automatically mounted as specified in the /etc/cdromd.conf file. Use the cdumount or cdeject command to unmount an automatically mounted CD or DVD. Use stopsrc -s cdromd to disable the CD/DVD automount daemon.
  2. For CacheFS, the remote file system that is to be cached locally must be exported such that the root ID of the local system is not remapped on the remote host to nobody (or the ID that the remote host uses as the anonymous user). For example, if host A were to export a file system /F, which would be mounted with CacheFS on host B, then the /etc/exports on host A would need to have an entry similar to: 
    /F -rw,root=B
or
/F -ro,root=B
    depending on the mount options used for the local CacheFS mount.
  3. Mounting a JFS file system on a read-only logical volume is not supported.
  4. Mounting a JFS2 file system with EAv1 on Trusted AIX® system converts the file system to EAv2.

Using mount on a JFS2 File System

The mount command can also be used to access a snapshot of a JFS2 file system as a directory tree. The snapshot on device is mounted read-only at directory. A snapshot can only be mounted once. When mounting a JFS2 file system with snapshots, the snapshots are activated.

You can use the System Management Interface Tool (SMIT) smit mount fast path to run this command.

Note: If the mount command encounters a Journaled File System (JFS) or Enhanced Journaled File System (JFS2) which was not unmounted before reboot, a replay of any JFS or JFS2 log records is attempted. In order to move a compatible JFS file system to a system running an earlier release of the operating system, the file system must always be unmounted cleanly prior to its movement. Failure to unmount first may result in an incompatible JFS log device. If the movement results in an unknown log device, the file system should be returned to the system running the latter operating system release, and fsck should be run on the file system.

Flags

Item Description
-a Mounts all file systems in the /etc/filesystems file with stanzas that contain the true mount attribute.
all Same as the -a flag.
-f Requests a forced mount during system initialization to enable mounting over the root file system.
-F AltFSfile Mounts on a file of an alternate file system, other than the /etc/filesystems file.
-n node Specifies the remote node that holds the directory to be mounted. The node can be specified as a colon-separated IPv6 address. If this is done with the node:directory format, the colon-separated IPv6 address must be enclosed in square brackets.
-p Mounts a file system as a removable file system. While open files are on it, a removable mounted file system behaves the same as a normally mounted file system. However, when no files are open (and no process has a current directory on the file system), all of the file system disk buffers in the file system are written to the medium, and the operating system forgets the structure of the file system.
-r Mounts a file system as a read-only file system, regardless of its previous specification in the /etc/filesystems file or any previous command-line options.
-t type Mounts all stanzas in the /etc/filesystems file that contain the type=type attribute and are not mounted. The type parameter specifies the name of the group.
-v vfsname Specifies that the file system is defined by the vfsname parameter in the /etc/vfs file.

File System Specific Options

Item Description
-o options Specifies options. Options entered on the command line should be separated only by a comma. The following file system-specific options do not apply to all virtual file system types:
atime
Turns on access-time updates. If neither atime nor noatime is specified, atime is the default value.
bsy
Prevents the mount operation if the directory to be mounted over is the current working directory of a process.
 
cio
Specifies the file system to be mounted for concurrent readers and writers. I/O on files in this file system will behave as if they had been opened with O_CIO specified in the open() system call. Using this option will prevent access in any manner other than CIO. It is impossible to use cached I/O on a file system mounted with the cio option. This means that mapping commands such as mmap() and shmat() will fail with EINVAL when used on any file in a file system mounted with the cio option. One side-effect of this is that it is impossible to run binaries out of a cio mounted file system, since the loader may use mmap().
Note: When you mount the file system by using the cio option, all applications must manage the serialization of files. Quotas are not supported by the cio option because quotas have their own serialization code.
 
dev
Specifies that you can open devices from this mount. If neither dev nor nodev is specified, dev is the default value.
dio
Specifies that I/O on the file system will behave as if all the files had been opened with O_DIRECT specified in the open() system call.
Note: Using the -odio or -ocio flags can help performance on certain workloads, but users should be aware that using these flags will prevent file caching for these file systems. Because readahead is disabled for these file systems, this may decrease performance for large sequential reads.
 
fmode=octal
Specifies the mode for a file and directory. The default is 755.
 
gid=gid
Specifies the GID that is assigned to files in the mount. The default is bin.
 
log=lvname
Specifies the full path name of the file system logging logical volume name where the following file-system operations are logged.
 
log=NULL

Turns off logging and flushing of metadata for JFS2 file systems. Metadata is not flushed to the disk until the file system is unmounted. If the system stops abnormally before the file system is unmounted, the metadata changes are lost.

The JFS2 file system depends on the log information for metadata consistency. If the system stops abnormally during the metadata flush process for the JFS2 file system when the unmount operation is in progress, the file system cannot be recovered to a consistent state upon system reboot. In this case, the file system must be re-created.

Attention: Because of the risk of data loss, use this flag with caution.
 
maxpout=value
Specifies the pageout level for files on this file system at which threads should be slept. If maxpout is specified, minpout must also be specified. Value must be non-negative and greater than minpout. The default is the kernel maxpout level.
 
minpout=value
Specifies the pageout level for files on this file system at which threads should be readied. If minpout is specified, maxpout must also be specified. Value must be non-negative. The default is the kernel minpout level.
 
noatime
Turns off access-time updates. Using this option can improve performance on file systems where a large number of files are read frequently and seldom updated. If you use the option, the last access time for a file cannot be determined. If neither atime nor noatime is specified, atime is the default value.
 
nocase
Turns-off case mapping. This is useful for CDROMs using the ISO 9660:1998/HSG standard.
 
nodev
Specifies that you cannot open devices from this mount. This option returns a value of ENXIO if a failure occurs. If neither dev nor nodev is specified, dev is the default value.
 
noguard
Mount the filesystem regardless of the current mountguard setting which would otherwise guard the filesystem against unsupported concurrent mounts in a PowerHA® or other clustering environment. If mountguard is enabled by the chfs or crfs command, the filesystem cannot be mounted if it appears to be mounted on another node or system. Specifying the noguard option temporarily overrides the mountguard setting.
 
norbr
Mounts the file system without the release-behind-when-reading capability. If none of the release-behind options are specified, norbrw is the default value.
 
norbrw
Mounts the file system without both the release-behind-when-reading and release-behind-when-writing capabilities. If none of the release-behind options are specified, norbrw is the default value.
 
norbw
Mounts the file system without the release-behind-when-writing capability. If none of the release-behind options are specified, norbrw is the default value.
 
nosuid
Specifies that execution of setuid and setgid programs by way of this mount is not allowed. This option returns a value of EPERM if a failure occurs. If neither suid nor nosuid is specified, suid is the default value.
 
rbr
Mount file system with the release-behind-when-reading capability. When sequential reading of a file in this file system is detected, the real memory pages used by the file will be released once the pages are copied to internal buffers. If none of the release-behind options are specified, norbrw is the default.
Note: When rbr is specified, the D_RB_READ flag is ultimately set in the _devflags field in the pdtentry structure.
 
rbw
Mount file system with the release-behind-when-writing capability. When sequential writing of a file in this file system is detected, the real memory pages used by the file will be released once the pages written to disk. If none of the release-behind options are specified, norbrw is the default.
Note: When rbw is specified, the D_RB_WRITE flag is set.
 
rbrw
Mount file system with both release-behind-when-reading and release-behind-when-writing capabilities. If none of the release-behind options are specified, norbrw is the default.
Note: If rbrw is specified, both the D_RB_READ and the D_RB_WRITE flags are set.
 
remount
Changes the mount options of a mounted file system. For JFS2 file systems, you can specify the following mount options with the remount option to change the settings of a mounted file system. For any mount options not specified, no change is made to the current corresponding settings of the file system.

atime, noatime; dev, nodev; maxpout, minpout; rbr, norbr; rbw, norbw; rbrw, norbrw, rw, ro, rox; suid, nosuid.

Note:
  1. External-snapshot mounted file systems cannot be remounted to read-write file systems.
  2. You cannot use the rw and ro remount options on a file system that is managed by data management application programming interface (DMAPI).
For NFS, there are three types of mount requests.
duplicate mount
If the node, object, mount point, and the options that are specified in the mount command are the same as those for an existing mount, the mount command returns information about a successful mount, but a new mount is not created.
new mount
If the remount option is not specified, the mount command creates a new mount. If the node, object, mount point, or the constant options that are specified in the mount command are different than those for the existing mounts, the mount command fails if the remount option is specified.
remount
If the node, object, and mount point are the same as those for a top-most mount, but the remount options are different, the remount operation modifies the mount options of an existing mount. In this case, NFS performs the remount operation.

A top-most mount does not have another mount on top of it. For remount requests, the following options can be modified: acdirmax, acdirmin, acregmax, acregmin, actimeo, fastattr, grpid, hard, intr, noac, nocto, nodev, nointr, nosuid, posix, retrans, ro, rsize, rw, secure, sec, soft, timeo, wsize, biods, extraattr, nodircache, prefer, otwattr, maxgroups, and proto. Other options are classified as constant options.
 
ro
Specifies that the mounted file is read-only, regardless of its previous option specification in the /etc/filesystems file or any previous command-line options. The default value is rw.
 
rw
Specifies that the mounted file is read/write accessible, regardless of its previous option specification in the /etc/filesystems file or any previous command-line options. The default value is rw.
 
snapshot
Specifies the device to be mounted is a snapshot. The snapped file system for the specified snapshot must already be mounted or an error message will display.
 
snapto=snapshot
Specifies the location to start a snapshot with the value of snapshot when mounting the specified JFS2 file system. The snapshot parameter specifies the name of an internal snapshot if the snapshot parameter does not included a forward slash (/), that is, no path information.
 
suid
Specifies that execution of setuid and setgid programs by way of this mount is allowed. If neither suid nor nosuid is specified, suid is the default value.
 
upcase
Changes case mapping from default lowercase to uppercase. This is useful for CDROMs using the ISO 9660:1998/HSG standard.
 
uid=uid
Specifies the UID that is assigned to files in the mount, the default is bin.
 
wrkgrp=workgroup
Specifies the workgroup that the SMB server belongs.

NFS Specific Options

Item Description
-o options Specifies options. Options you enter on the command line should be separated only by a comma, not a comma and a space. The following NFS-specific options do not apply to all virtual file system types:
acdirmax=n
Holds cached attributes for no more than n seconds after directory update. The default is 60 seconds.
 
acdirmin=n
Holds cached attributes for at least n seconds after directory update. The default is 30 seconds.
 
acl
Requests using the Access Control List RPC program for this NFS mount. If the acl option is used, the ACL RPC program is used only if the NFS server provides it. The default is noacl.
 
acregmax=n
Holds cached attributes for no longer that n seconds after file modification. The default is 60 seconds.
 
acregmin=n
Holds cached attributes for at least n seconds after file modification. The default is 30 seconds.
 
actimeo=n
Sets minimum and maximum times for regular files and directories to n seconds. If this option is set, it overrides any settings for the acregmin, acregmax, acdirmin, and acdirmax options.
 
bg
Attempts mount in background if first attempt is unsuccessful. The default value is fg.
 
biods=n
Sets the maximum number of biod threads that perform asynchronous I/O RPC requests for an NFS mount. The maximum value that can be set is 128. Values greater than 128 are limited to 128 within the NFS client. The NFS client dynamically manages the number of running biod threads up to the maximum based on activity. The default maximums for the different NFS protocols are 7 for NFS version 2 and 32 for NFS version 3 and NFS version 4. These defaults are subject to change in future releases.
 
cio
Specifies the file system to be mounted for concurrent readers and writers. I/O on files in this file system will behave as if they had been opened with O_CIO specified in the open() system call. Using this option will prevent access in any manner other than CIO. It is impossible to use cached I/O on a file system mounted with the cio option. This means that mapping commands such as mmap() and shmat() will fail with EINVAL when used on any file in a file system mounted with the cio option. One side-effect of this is that it is impossible to run binaries out of a cio mounted file system, since the loader may use mmap().
Note: When you mount the file system by using the cio option, all applications must manage the serialization of files. Quotas are not supported by the cio option because quotas have their own serialization code.
 
cior
Specifies to allow read-only files to open in the file system. I/O on files in this file system will behave as if they had been opened with O_CIO | O_CIOR specified in the open() system call. Using this option will prevent access in any manner other than O_CIO | O_CIOR and read-only. An attempt to open with O_CIO only will also fail. This option can only be used in conjunction with cio.
 
dio
Specifies that I/O on the file system will behave as if all the files had been opened with O_DIRECT specified in the open() system call.
Note: Using the -odio or -ocio flags can help performance on certain workloads, but users should be aware that using these flags will prevent file caching for these file systems. Because readahead is disabled for these file systems, this may decrease performance for large sequential reads.
 
fastattr
Bypasses the requirement that files currently being written will be sent to the server before the attributes of the file is read. This option is to be used with caution, since it will cause the client to assume that the file data that has not yet reached the server will be written without problem. In case of write errors, the client and server will have different opinions on what the size of the file really is. Likewise, a client will not be aware of attribute changes to the file being made by another client, so this option must not be used in environments where two clients are writing to the same files.
 
fg
Attempts mount in foreground if first attempt is unsuccessful. fg is the default value.
 
grpid
Directs any file or directory created on the file system to inherit the group ID of the parent directory.
 
hard
Retries a request until server responds. The option is the default value.
 
intr
Allows keyboard interrupts on hard mounts.
 
llock
Requests that files lock locally at the NFS client. NFS network file locking requests are not sent to the NFS server if the llock option is used.
 
maxgroups=n
Indicates that NFS RPC calls using AUTH_UNIX may include up to n member groups of information. Using this option to increase the number of member groups beyond the RPC protocol standard of 16 will only work against servers that support more than 16 member groups. Otherwise, the client will experience errors.

Values below 16 or greater than 64 will be ignored. By default, the protocol standard maximum of 16 is adhered to. AIX NFS servers will accept and process AUTH_UNIX credentials with up to 64 groups starting with AIX 5L Version 5.2 with the 5200-01 Recommended Maintenance package. The actual number of member groups sent by the NFS client is dependent on the number of groups the involved user is a member of, and may be limited by the length of the NFS client's hostname (which is included in the AUTH_UNIX information).
 
noac
Specifies that the mount command performs no attribute or directory caching. If you do not specify this option, the attributes (including permissions, size, and timestamps) for files and directories are cached to reduce the need to perform over-the-wire NFSPROC_GETATTR Remote Procedure Calls (RPCs). The NFSPROC_GETATTR RPC enables a client to prompt the server for file and directory attributes. The acregmin, acregmax, acdirmin, and acdirmax options control the length of time for which the cached values are retained.
 
noacl
Specifies not to use the Access Control List RPC program for this NFS mount request. The default is noacl.
 
nointr
Specifies no keyboard interrupts allowed on hard mounts.
 
port=n
Sets server Internet Protocol (IP) port number to n. The default value is the 2049.
 
posix
Requests that pathconf information be exchanged and made available on an NFS Version 2 mount. Requires a mount Version 2 rpc.mountd at the NFS server.
 
proto=[udp|tcp]
Specifies the transport protocol. The default is tcp. Use the proto=[udp|tcp] option to override the default.

proto=udp cannot be specified if vers=4.
 
retrans=n
Sets the number of NFS transmissions to n. The default value is 5. The retrans setting determines how many times the NFS client retransmits a given UDP RPC request to an NFS server for file system operations. The retrans setting is not used during communication with the NFS server rpc.mountd service when processing NFS version 2 and 3 mounts. Retries to rpc.mountd are controlled with the retry mount option.
 
retry=n
Sets the number of times the mount is attempted to n; the default value is 1000. When the retry value is 0, the system makes 10,000 attempts.
 
rsize=n
Sets the read buffer size to n bytes. Beginning with AIX Version 6.1, the default value is 64 KB and the maximum value is 512 KB when using Version 3 and Version 4 of the NFS protocol.
 
secure
Specifies that the mount command uses Data Encryption Standard (DES) for NFS transactions. Data Encryption Standard (DES) is not supported in NFS Version 4, use krb5 instead.
  
sec=flavor[:flavor...]
Specifies a list of security methods that may be used to access files under the mount point. Allowable flavor values are:
sys
UNIX authentication. This is the default method.
dh
DES authentication. Data Encryption Standard (DES) is not supported in NFS Version 4, use krb5 instead.
krb5
Kerberos. Authentication only.
krb5i
Kerberos. Authentication and integrity.
krb5p
Kerberos. Authentication, integrity, and privacy.

The secure option may be specified, but not in conjunction with a sec option. The secure option is deprecated and may be eliminated in a future release. Use sec=dh instead.
 
sec=[flavor1:...:flavorn]
The sec option specifies the security flavor list for the NFS mount. The available flavors are des, unix, sys, krb5, krb5i, and krb5p. This option only applies to AIX 5.3 or later.
 
shortdev
Specifies that you are mounting a file system from a host that does not support 32-bit device special files.
 
soft
Returns an error if the server does not respond. The default value is hard.
 
timeo=n
Sets the Network File System (NFS) time out period to n tenths of a second. For TCP mounts, the default timeout is 100, which equals 10 seconds. For UDP mounts, the default timeout is 11, which equals 1.1 seconds, but varies depending on the NFS operation taking place. For UDP mounts, the timeout will increase for each failed transmission, with a maximum value of 20 seconds. Each transmission will be attempted twice, after which the timeout value is updated. The timeo option does not apply to communication from the NFS client to the rpc.mountd service on NFS servers. A timeout of 30 seconds is used when making calls to rpc.mountd.
 
vers=[2|3|4]
Specifies NFS version. The default is the version of NFS protocol used between the client and server and is the highest one available on both systems. If the NFS server does not support NFS Version 3, the NFS mount will use NFS Version 2. Use the vers=[2|3|4] option to select the NFS version. By default, the NFS mount will never use NFS Version 4 unless specified. The vers=4 only applies to AIX 5.3 or later.
 
wsize=n
Sets the write buffer size to n bytes. Beginning with AIX Version 6.1, the default value is 64 KB and the maximum value is 512 KB when using Version 3 and Version 4 of the NFS protocol.

CacheFS Specific Options

The CacheFS-specific version of the mount command mounts a cached file system; if necessary, it NFS-mounts its back file system. It also provides a number of CacheFS-specific options for controlling the caching process.

To mount a CacheFS file system, use the mount command with the -V flag followed by the argument. The following mount flags are available.

The following arguments to the -o flag are specifically for CacheFS mounts. Options you enter on the command line should be separated only by a comma, not a comma and a space.
Note: The backfstype argument must be specified.
Item Description
-o Specifies options.
acdirmax=n
Specifies that cached attributes are held for no more than n seconds after directory update. Before n seconds, CacheFS checks to see if the directory modification time on the back file system has changed. If it has, all information about the directory is purged from the cache and new data is retrieved from the back file system. The default value is 60 seconds.
 
acdirmin=n
Specifies that cached attributes are held for at least n seconds after directory update. After n seconds, CacheFS checks to see if the directory modification time on the back file system has changed. If it has, all information about the directory is purged from the cache and new data is retrieved from the back file system. The default value is 30 seconds.
 
acregmax=n
Specifies that cached attributes are held for no more than n seconds after file modification. After n seconds, all file information is purged from the cache. The default value is 30 seconds.
 
acregmin=n
Specifies that cached attributes are held for at least n seconds after file modification. After n seconds, CacheFS checks to see if the file modification time on the back file system has changed. If it has, all information about the file is purged from the cache and new data is retrieved from the back file system. The default value is 30 seconds.
 
actimeo=n
Sets acregmin, acregmax, acdirmin, and acdirmax to n.
 
backfstype=file_system_type
The file system type of the back file system (for example, nfs).
 
backpath=path
Specifies where the back file system is already mounted. If this argument is not supplied, CacheFS determines a mount point for the back file system.
 
cachedir=directory
The name of the cache directory.
 
cacheid=ID
ID is a string specifying a particular instance of a cache. If you do not specify a cache ID, CacheFS will construct one.
 
demandconst
Enables maximum cache consistency checking. By default, periodic consistency checking is enabled. When you enable demandconst, it checks on every read and write.
Note: If this option is used the first time a specific CacheFS is mounted, then the option must also be specified for subsequent mounts. There is state information stored in the cache control files that enforces consistent use of this option.
 
local_access
Causes the front file system to interpret the mode bits used for access checking instead or having the back file system verify access permissions. Do not use this argument with secure NFS.
 
noconst
Disables cache consistency checking. By default, periodic consistency checking is enabled. Specify noconst only when you know that the back file system will not be modified. Trying to perform cache consistency check using cfsadmin-s will result in error. demandconst and noconst are mutually exclusive.
Note: If this option is used the first time a specific CacheFS is mounted, then the option must also be specified for subsequent mounts. There is state information stored in the cache control files that enforces consistent use of this option.
 
purge
Purges any cached information for the specified file system.
Note: If this option is used the first time a specific CacheFS is mounted, then the option must also be specified for subsequent mounts. There is state information stored in the cache control files that enforces consistent use of this option.
 
rw | ro
Read-write (default) or read-only.
 
suid | nosuid
Allows (default) or disallows set-uid execution
 
write-around | non-shared
Writes modes for CacheFS. The write-around mode (the default) handles writes the same as NFS does; that is, writes are made to the back file system, and the affected file is purged from the cache. You can use the non-shared mode when you are sure that no one else will be writing to the cached file system.
Note: If this option is used the first time a specific CacheFS is mounted, then the option must also be specified for subsequent mounts. There is state information stored in the cache control files that enforces consistent use of this option.
 
mfsid
Turns on global view. In NFS v4 system, you can traverse through the exported namespace on the server side. You need to specify this option to go over the file system.
Restriction: mfsid is an option if the backend file system for CacheFS is NFS v4.
-V Mounts a CacheFS file system.

Server Message Block (SMB) client file system specific options

Item Description
-o options Specifies options for mounting the SMB client file system. Options that you enter on the command line must be separated only by a comma. Do not insert a space before or after a comma. The following options are available for the SMB client file system:
fmode
Sets a file or directory to octal mode for access permissions. The default value is 755.
uid
Assigns a user ID to files during the mount operation. The default value is root.
gid
Assigns a group ID to files during the mount operation. The default value is system.
wrkgrp
Specifies the workgroup to which the SMB server belongs. This parameter is mandatory to mount the SMB client file system.
port
Specifies the port number. The valid values are 445 and 139. The default value is 445. Port 139 is supported only when the specified server address is in IPv4 format.
Note: encryption option is not supported when the port specified is 139.
pver
Specifies version of the SMB protocol that is used to communicate with the SMB server. The valid values are 2.1,3.0.2 and auto. For the value auto, the SMB protocol version 2.1 or version 3.0.2 is used based on the specified SMB server.
signing
Specifies whether the file system in the SMB client needs digital signature for communication with the SMB server filesystem. The valid values are enabled and required. When this parameter is set to enabled, the file system in the SMB client does not digitally sign the data packets unless the file system in the SMB server needs digital signatures for communication with the file system in the SMB server. When this is set to required, the file system in the SMB client must digitally sign the data packets for communication with the file system in the SMB server. If you do not specify the value for the signing parameter by using the mount command, a default value is used from the tunable parameter values of the kernel that are set by using the smbctune command.
secure_negotiate
Specifies whether the file system in the SMB client needs secure dialect negotiation capability. SMB Dialect 3.0.2 implements secure dialect negotiation to protect against security-downgrade attacks. The valid values are desired, required, and disabled. If you do not specify the value by using the mount command, a default value is used from tunable parameter values of the kernel that are set by using the smbctune command.
encryption
Specifies whether the file system in the SMB client requires data encryption. The valid values are desired, required, and disabled. If you do not specify the value by using the mount command, a default value is used from the tunable parameter values of the kernel that are set by using the smbctune command.
Note: encryption option is not supported when the port specified is 139.
spn
Specifies the service principal name (SPN) that must be used in the SMB client mount points. The format of the spn parameter is cifs/<smbServerHostName>, where smbServerHostName is the fully qualified domain name (FQDN) of the SMB server or the name that the Kerberos resolves as the SMB server. By default, SPN is constructed automatically by the SMB client file system as cifs/<smbServerHostName>.

If the options that are used with the mount command (pver, signing, secure_negotiate, or encryption) are unspecified by using the -o flag, the default values for the mount command options are initialized by using the new values of the kernel tunable parameters (smbc_protocol_version, smbc_signing, smbc_secure_negotiate, smbc_encryption). The kernel tunable parameters are initialized from tunable parameters defined in the smbctune.conf file. These parameters can also be modified by using the smbctune command.

The following table shows the kernel tunable parameters of the mount command and the corresponding kernel tunable parameters that can be set in the smbctune.conf file:
Options of the -o flag (mount command) Corresponding kernel tunable parameter of the smbctune.con file Valid values
pver smbc_protocol_version 2.1, 3.0.2, auto
signing smbc_signing enabled, required
secure_negotiate smbc_secure_negotiate desired, required, disabled
encryption smbc_encryption desired, required, disabled

Security

Attention RBAC users and Trusted AIX users: This command can perform privileged operations. Only privileged users can run privileged operations. For more information about authorizations and privileges, see Privileged Command Database in Security. For a list of privileges and the authorizations that are associated with this command, see the lssecattr command or the getcmdattr subcommand.

Examples

  1. To list the mounted file systems, enter the following command: 
    mount
    This command produces output similar to the following: 
    node   mounted          mounted over  vfs    date              options   
----   -------          ------------ ---  ------------   -------------------
       /dev/hd0         /            jfs   Dec 17 08:04   rw, log  =/dev/hd8
       /dev/hd3         /tmp         jfs   Dec 17 08:04   rw, log  =/dev/hd8
       /dev/hd1         /home        jfs   Dec 17 08:06   rw, log  =/dev/hd8
       /dev/hd2         /usr         jfs   Dec 17 08:06   rw, log  =/dev/hd8
sue    /home/local/src  /usr/code    nfs   Dec 17 08:06   ro, log  =/dev/hd8
    For each file system, the mount command lists the node name, the device name, the name under which it is mounted, the virtual-file-system type, the date and time it was mounted, and its options.
  2. To mount all default file systems, enter the following command: 
    mount all
    This command sequence mounts all standard file systems in the /etc/filesystems file marked by the mount=true attribute.
  3. To mount a remote directory, enter the following command: 
    mount -n nodeA /home/tom.remote /home/tom.local
    This command sequence mounts the /home/tom.remote directory located on nodeA onto the local /home/tom.local directory. It assumes the default VfsName parameter=remote, which must be defined in the /etc/vfs file.
  4. To mount a file or directory from the /etc/filesystems file with a specific type, enter the following command: 
    mount -t remote
    This command sequence mounts all files or directories in the /etc/filesystems file that have a stanza that contains the type=remote attribute.
  5. To CacheFS-mount the file system which is already NFS-mounted on /usr/abc, enter the following command: 
    mount -V cachefs -o backfstype=nfs,backpath=/usr/abc,
cachedir=/cache1 server1:/user2 /xyz

    The lines similar to the following appear in the /etc/mnttab file after the mount command is executed:

    server1:/user2 /usr/abc nfs
/usr/abc /cache1/xyz cachefs backfstype=nfs
  6. To mount a snapshot, enter the following command: 
    mount -o snapshot /dev/snapsb /home/janet/snapsb
    This command mounts the snapshot contained on the /dev/snapsb device onto the /home/janet/snapsb directory.
  7. To mount a file system and create a snapshot, enter the following command: 
    mount -o snapto=/dev/snapsb /dev/sb /home/janet/sb
    This command mounts the file system contained on the /dev/sbdevice onto the /home/janet/sb directory and creates a snapshot for the file system on the /dev/snapsbdevice.
  8. To access files on an SMB server as a local file system, enter the following command: 
    mount -v cifs -n pezman/user1/pass1 -o uid=201,fmode=750 /home /mnt
  9. To mount an SMB client file system as a local mount point, enter the following command:
    mount -v smbc -n llm140.xyz.com/cec102usr1/Passw0rd     \
-o wrkgrp=SMB_21.FVT,port=445,signing=required /some_share /mnt
    Where, llm140.xyz.com is the Windows server, cec102usr1 is the Kerberos user name, Passw0rd is the password of the Kerberos user, SMB_21.FVT is the workgroup, some_share is the share point on the Windows system, and /mnt is the local mount point.
  10. To remount the mounted read-only JFS2 file system to a read-write file system, enter the following command: 
    mount -o remount,rw fsname
  11. To mount all on a file /tmp/fs1 of an alternate file system, enter the following command:
    mount -F /tmp/fs1 all

Files

Item Description
/etc/filesystems Lists the known file systems and defines their characteristics.
/etc/vfs Contains descriptions of virtual-file-system types.