mmlinkfileset command

Creates a junction that references the root directory of a GPFS™ fileset.

Synopsis

mmlinkfileset Device FilesetName [-J JunctionPath]

Availability

Available with IBM Spectrum Scale™ Standard Edition or higher.

Description

The mmlinkfileset command creates a junction at JunctionPath that references the root directory of FilesetName. The junction is a special directory entry, much like a POSIX hard link, that connects a name in a directory of one fileset, the parent, to the root directory of a child fileset. From the user's viewpoint, a junction always appears as if it were a directory, but the user is not allowed to issue the unlink or rmdir commands on a junction. Instead, the mmunlinkfileset command must be used to remove a junction.

If JunctionPath is not specified, the junction is created in the current directory with the name FilesetName. The user may use the mv command on the directory to move to a new location in the parent fileset, but the mv command is not allowed to move the junction to a different fileset.

For information on GPFS filesets, see the IBM Spectrum Scale: Administration Guide.

Parameters

Device: The device name of the file system that contains the fileset.
File system names need not be fully-qualified. fs0 is as acceptable as /dev/fs0.
FilesetName: Specifies the name of the fileset to be linked. It must not already be linked into the namespace.
There are no restrictions on linking independent filesets, but a dependent fileset can only be linked inside its own inode space.
-J JunctionPath: Specifies the name of the junction. The name must not refer to an existing file system object.

Exit status

0: Successful completion.
nonzero: A failure has occurred.

Security

You must have root authority to run the mmlinkfileset command.

The node on which the command is issued must be able to execute remote shell commands on any other node in the cluster without the use of a password and without producing any extraneous messages. For more information, see Requirements for administering a GPFS file system.

Examples

This command links fileset fset1 in file system gpfs1 to junction path /gpfs1/fset1:

mmlinkfileset gpfs1 fset1 -J /gpfs1/fset1

The system displays output similar to:

Fileset 'fset1' linked at '/gpfs1/fset1'.

To confirm the change, issue this command:

mmlsfileset gpfs1