NAME
fstadm — defines and manages file system stack templates
SYNOPSIS
/usr/sbin/fstadm create
[-o]
-f
filename
[-n
name]
/usr/sbin/fstadm create
[-o]
-t template_string
-n name
/usr/sbin/fstadm list
/usr/sbin/fstadm display
template_name
/usr/sbin/fstadm delete
template_name
/usr/sbin/fstadm fdel
template_name
/usr/sbin/fstadm help
DESCRIPTION
The
fstadm
command performs basic administrative operations on file system stack
templates.
Operations include creating and deleting templates, listing all
templates on the system, and displaying the contents of templates.
File system stack templates are used to describe the structure of a file system
module stack.
They contain information about the modules on a stack and the
mount options for each module on the stack.
All stack templates on a system reside in the system's stack template database.
The only supported way to access and edit templates in the system template
database is to use the
fstadm
command.
The
fstadm
command also validates all templates at the time that they are created, to make
sure that any dependency and compatibility constraints for modules on a stack
are not violated.
Dependency and compatibility constraints are specified by
individual module developers, and
fstadm
enforces the constraints as needed.
Note that end users do not need to be
concerned about what constraints exist and how they are implemented: they only
need to use
fstadm
to create all their templates, and
fstadm
will report on any problems with a user's proposed stack template.
It is then easy to modify the inputs to
fstadm
to build a correctly validated template.
Once a stack template is created and exists in the system template database,
it can be used at mount time by specifying its name as a
stackfs
mount option.
For example, the command below will mount the desired
hfs
file system, with a stack described by template
mytemplate
built above it.
The file system on
/mnt
will now have the features of
hfs
plus those of all of the modules on the stack described by
mytemplate.
mount -F hfs -o largefiles,stackfs=mytemplate /dev/dsk/c2t0d0 /mnt
Note that templates do not
include information about the base file system to be mounted (e.g.
vxfs
or
hfs),
so the base file system must still be specified on the
mount
command line in the traditional way.
(Support for templates that include base file
systems is not included in the current versions of HP-UX.)
fstadm
can be invoked only by a user who has appropriate privileges.
The behavior of the
fstadm
command depends upon the command name keyword specified as the first operand.
Command Keywords and Options
The following command keywords, arguments, and options are currently supported.
- create -f | -t
Creates a new template.
To describe a template, this
command takes two types of input:
a text file that describes a template, specified with the
-f
option, or
a string that describes a template directly in the command line,
specified with the
-t
option.
The
-t
option cannot be used in conjunction with the
-f
option.
A template can contain information about the mount options to use
at each level of a stack. For information about the specific
mount options that are available for each stackable file system
module, consult the manpage for the module itself.
The
create
command uses the information in its input to validate and
build a new template.
If the new template's structure fails validation, this
command will abort and print an error message describing the problem.
If validation succeeds, this command will create the template in the system
template database and make it available for use with future mounts.
The arguments that can be used with the
create
keyword are:
- -f filename
Specifies the name of a text file that describes the contents of a stack
template.
Information in the text file will be used as a guide to construct
the desired stack template.
The format of each line in the text file is:
module options
That is, each line of the text file describes one level of the desired stack.
Within each line, a module and its mount options are separated by a single
space character.
The first line of the file represents the top of the stack,
and the last line of the file represents the bottom.
The format of these text
files is identical to that of the output of the
display
command keyword.
- -t template_string
Specifies the contents of a stack template.
The format for this string is:
module1:options1;module2:options2;...;moduleN:optionsN
That is, an entire stack is described within the string, and each level of a
stack is separated by a semicolon
(;).
Within a level, a module and its mount options are separated by a colon
(:).
(But the colon does not need to be included for modules without mount
options.)
The leftmost module in the string represents the top of the stack,
and the right-most module represents the bottom of the stack.
- -n name
Specifies the name of the template to be created.
The maximum supported length for the template name is
128
characters.
This is a required argument whenever
-t
is used.
For
-f,
if it is omitted,
the name of the new template
defaults to the name of the file specified with
-f.
- -o
Overwrite option.
If a template with the same name as the new template being
created already exists, overwrites the old template.
If this option is not
specified, the
create
command will fail whenever a template of the same name already exists.
Note
however that if a template of the same name exists AND is currently in use (in
/etc/fstab
or
/etc/mnttab),
the
create
command will always fail, even if
-o
was specified.
The rationale for this is that templates for stacks that are
currently in use cannot be allowed to change.
- list
List all the templates in the system.
This command displays the names of all
templates currently stored in the system template database.
Each template name is listed in its own line of output.
- display template_name
Displays the contents of the specified template.
This command will display the contents of the
named template as text output, with each level of the stack described by one
line of output.
That is, each line of output will contain a module name, a
space, and then the module's mount options (if any).
The first line displayed
represents the top of the stack, and the last line represents the bottom of the stack.
Optionally, if it is redirected to a file, this output can also be used as
input to
fstadm create
via the
-f
option.
- delete template_name
Deletes the specified template from the system template database.
If the template is
currently in use (in
/etc/fstab
or
/etc/mnttab),
deletion is not allowed.
In all other cases, the template will be removed from
the system template database after user confirmation of the delete operation.
(Template deletion is permanent and irrecoverable.)
- fdel template_name
Forced delete of the specified template.
Identical to
delete,
but performs the deletion without asking for user confirmation. This command
is provided for use by non-interactive scripts.
- help
Interactive help utility.
Displays basic information about the various
fstadm
command keywords.
RETURN VALUE
fstadm
exits with one of the following values:
- 0
Successful completion.
- >0
An error condition occurred.
Because
fstadm
is primarily an interactive
command, an explanation of the error will be printed to standard error.
EXAMPLES
List all the file system stack templates currently on the system:
Display the contents of the stack template named
mytemplate:
fstadm display mytemplate
Create a new template describing a stack that contains stacked modules named
verfs
and
secfs
(with module
verfs
having a mount option set to 2), and name the template
myfs:
fstadm create -t verfs:option=2;secfs -n myfs
Delete the file system stack template named
mytemplate:
AUTHOR
fstadm
was developed by HP.
Printable version
