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mkfdmn(8)
NAME
mkfdmn - Creates a new AdvFS domain
SYNOPSIS
/sbin/mkfdmn [-F] [-l num_pages] [-o] [-p num_pages] [-r] [-x num_pages]
[-V3 | -V4] special domain
OPTIONS
-F Ignores overlapping partition or block warnings.
-l num_pages
Sets the number of pages in the log file. AdvFS rounds this number up
to a multiple of four.
-o Allows reuse of an existing domain name. It destroys the existing
domain and creates a new domain with the existing domain name.
-p num_pages
Sets the number of pages to preallocate for the bitfile metadata table
(BMT). The default is 0 (zero) pages. This option may be useful if you
have chosen the -V3 option; it is not applicable for domains created
with V4.
-r Specifies the domain as the local root domain. This prevents multiple
volumes in the root domain. AdvFS supports only one volume in the
local root domain. This does not apply to the cluster root domain.
-V3 | -V4
If you specify -V3, creates an AdvFS domain that uses the on-disk
formats employed by AdvFS prior to the release of OS Version 5.0; that
is, creates a domain with a domain version number (DVN) of 3. If you
specify -V4, creates an AdvFS domain that uses the on-disk formats
employed by AdvFS starting with the release of OS Version 5.0; that is,
creates a domain with a DVN of 4. If neither option is specified, the
default action is to use the DVN 4 on-disk formats for the domain.
-x num_pages
Sets the number of pages by which the BMT extent size grows. The value
must be greater than or equal to 128 pages. The default is 128 pages.
This option may be useful if you have chosen the -V3 option; it is not
applicable for domains created with the -V4 option
OPERANDS
special
Specifies the block special device name, such as /dev/disk/dsk1c, or
the LSM volume name of the initial volume that you use to create the
domain. This command supports short hand names for block special
devices. For example, if you enter dsk2g, it will be translated to
/dev/disk/dsk2g.
domain
Specifies the name of the domain.
DESCRIPTION
The mkfdmn command creates a domain, which is a logical construct
containing both physical volumes (disks or disk partitions) and filesets.
When you create a domain, you must specify one volume. This can be an LSM
volume.
The minimum size of an AdvFS domain depends, to some degree, on the size of
the disk or logical volume on which it is created. It is generally not
possible to create a domain smaller than 6 or 7 megabytes. If you attempt
to create a domain on a disk or logical volume that is too small, AdvFS
will display errors like the following:
bs_disk_init: disk is too small
mkfdmn: domain init error ENO_MORE_BLKS (-1040)
mkfdmn: can't create new domain 'small_domain'
If you try to add a volume with partitions that overlap any volumes used by
another file system (as indicated on the disk label), including UFS, AdvFS,
and LSM, the mkfdmn command displays a message asking if you want to
continue:
Partition(s) which overlap /dev/rdisk/dsk10a are marked in use.
If you continue with the operation you can
possibly destroy existing data.
CONTINUE? [y/n] y
Use the -F option to disable testing for overlap.
If you are creating a domain and requesting a partition that overlaps an
existing /etc/fdmns entry, the mkfdmn command will not create the
partition. If the partition is in use, you will receive a message asking
if you want to override. If you want to override without a prompt, use the
-F option.
Caution
Existing data on the volume you assign to a new domain is destroyed
when the domain is created.
The mkfdmn command does not create a file system that you can mount. In
order to mount an AdvFS file system, the domain must contain one or more
filesets. Run the mkfset command to create at least one fileset within the
new domain. You can access the domain as soon as you mount one or more
filesets. For more information about creating filesets, see mkfset(8).
To remove a domain, dismount all filesets in the domain you want to remove.
Then use the rmfdmn command to remove the domain. Using the rmfdmn command
is preferable to removing the directory defining a domain because the
command changes the disk label information to indicate that the partition
is no longer in use by AdvFS.
If the /etc/fdmns directory is lost or the volumes of a domain are moved to
a different system, you can use the advscan command to re-create a domain.
See advscan(8).
Domains created with the -V3 option that contain a very large number of
files may need added BMT mcells (similar to inodes in UFS). By default,
AdvFS attempts to grow the BMT by 128 pages each time additional mcells are
needed. This may cause the metadata storage to become very fragmented,
resulting in a premature "out of disk space" error.
You can reduce the amount of BMT metadata fragmentation for file domains
created with the -V3 option either by preallocating space for the BMT or by
increasing the number of pages that the system attempts to grow the BMT
each time space is needed. Use the -p option to preallocate all the BMT
space you expect the file domain to need. Note that space that is
preallocated cannot be deallocated. Use the -x option to specify how many
pages the BMT should be extended each time additional mcells are needed.
The following table provides guidelines for BMT growth size in pages (-x
option) and BMT preallocation (-p option) that you may want to use if you
are creating domains with the -V3 option. If your estimated number of files
is greater than those listed in the table, keep doubling the last table
entry until you get a value that is close to your needs.
____________________________________________________________________
Number of Files
BMT Growth Size in
Pages
BMT Preallocation Size
in Pages
____________________________________________________________________
Less than 50,000 Default (128) 3,600
100,000 256 7,200
200,000 512 14,400
300,000 768 21,600
400,000 1024 28,800
800,000 2048 57,600
____________________________________________________________________
NOTES
If you have domains created on systems prior to Version 5 or domains
created with the V3 option of mkfdmn, use the -p or -x option to grow the
BMT extent allocations. You must use the same option with the same number
of pages when you add a volume to the file domain with the addvol command.
See addvol(8) for information about adding a volume to a file domain.
Use a value in the -x num_pages argument that maintains the following
relationship between the BMT extent size (the number of pages for the -x
parameter) and the log file size (the number of pages for the -l
parameter):
BMT extent size <= (log file size * 8184) / 4
It takes about one minute to process 5000 BMT extent size pages with the -x
option. A process that initiates a BMT extent size operation must take
into account that very large values for -x will take a long time to
complete.
This command supports shorthand names for LSM volume names. For example, if
you enter the following:
# mkfdmn testdg.vol1 dom1
the volume name will be translated to:
# mkfdmn /dev/vol/testdg/vol1 dom1
RESTRICTIONS
You must be the root user to use this command.
All white space characters (tab, line feed, space, and so on) and the / # :
* ? characters are invalid for domain names.
ERRORS
Command execution continues after the following warnings are displayed:
· mkfdmn: Invalid value for -x mkfdmn: Setting to minimum value of 128
Explanation:
You have entered an invalid value for the -x option.
· mkfdmn: Invalid value for -p mkfdmn: Setting to minimum value of 0.
Explanation:
You have entered an invalid value for the -p option.
EXAMPLES
The following example creates the accounts_dmn domain with the special
device /dev/disk/dsk1c as the initial volume:
# mkfdmn /dev/disk/dsk1c accounts_dmn
Until you create and mount a fileset for the accounts_dmn domain, you
cannot access the file system.
FILES
/etc/fdmns
Contains domain names and devices.
SEE ALSO
Commands: addvol(8), advscan(8), mkfset(8), mount(8), rmfdmn(8),
showfdmn(8)
Files: fdmns(4)
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