.TH jfs_mkfs 8 "March 9, 2005" " " "JFS file system creation"

.SH NAME
.B jfs_mkfs
\- create a JFS formatted partition

.SH SYNOPSIS
.B jfs_mkfs
[options]
.I device
[ blocks ]

.SH DESCRIPTION
.PP
.B jfs_mkfs
is used to create (format) a JFS partition.
.B jfs_mkfs
must be run as root.

.PP
.I device
is the special file name corresponding to the actual device
.RI (e.g. " /dev/hdb1" )
on which a JFS file system and/or JFS journal will be created.
.I blocks
is the number of blocks to be used for the file system.  If omitted,
.B jfs_mkfs
automatically figures the file system size.

.PP
The default block size is
.BR 4096 "."

.SH WARNING
.PP
.B jfs_mkfs
will destroy all data on the specified device!

.SH OPTIONS

.\"*********************************************
.\"*  block size has not been implemented yet  *
.\"*********************************************
.\".TP
.\".BI \-b " block_size"
.\"Set the block size for a new JFS partition
.\".RS
.\"
.\"Options for
.\".I block_size
.\"are:
.\".BR 512 ","
.\".BR 1024 ","
.\".BR 2048 ", or"
.\".BR 4096 "."
.\"
.\"Using small blocks (rather than large blocks) is more space efficient because it
.\"reduces the amount of internal fragmentation within files and directories.
.\"However, using large blocks (rather than small blocks) is more performance efficient
.\"because block allocation activities may occur less often .
.\"
.\"If the
.\".B \-b
.\"option is not used, the default block size is
.\".BR 4096 "."
.\".RE

.TP
.BI \-c
Check the device for bad blocks before building the file system.

.\"**********************************
.\"*  use -q (quiet) instead of -f  *
.\"**********************************
.\".TP
.\".BI \-f
.\"Force - do not ask for confirmation before creating the file system.

.TP
.BI -j " journal_device"
Create the external JFS journal on
.I journal_device
, create the JFS file system on
.I device
, and attach the external journal to the file system.

.TP
.BI \-J " journal-options"
Create the JFS journal on its own device or attach an external JFS journal
to the JFS file system using options specified on the command-line.
The following journal options are supported:
.RS 1.2i
.TP
.BI journal_dev
Create an external JFS journal on the given device.
.TP
.BI device= external-journal
Attach an existing external JFS journal located on
.I external-journal
to the JFS file system that will be created on
.IR device .
The external
journal must already have been created using the command
.IP
.B jfs_mkfs -J journal_dev
.I external-journal
.IP
Attach the external journal to the file system being created by using the command
.IP
.BI "jfs_mkfs -J device="external-journal
.I device
.IP
Instead of specifying a device name directly,
.I external-journal
can also be specified by either
.BI LABEL= label
or
.BI UUID= UUID
to locate the external journal by either the volume label or UUID
stored in the JFS external log superblock at the start of the journal.  Use
.BR jfs_tune (8)
to display a journal device's volume label and UUID.  (See the
.BR -l ,
.BR -L ,
and
.B -U
options of
.BR jfs_tune (8).)
.RE
.IP
Only one of the
.BR journal_dev " or " device=
options can be given per
.B jfs_mkfs
issuance.

.TP
.BI -L " volume_label"
Set the volume label for the newly formatted device.
.IP
If
.BI -L " volume_label"
is used along with
.BR "-J journal_device" ,
the volume label of the specified external journal device
will be set to
.IR volume_label .
Otherwise, the volume label of the JFS file system will be set to
.IR volume_label .

.TP
.B \-O
Provide case-insensitive support for compatibility with OS/2.

.TP
.BI \-q
Quiet execution - do not ask for confirmation before creating the file system.

.TP
.BI -s " log_size"
Set the log size (in megabytes) of the inline log.  If the
.B \-s
option is not used, the default log size is 0.4% of the aggregate size.

.TP
.BI \-V
Print version information and exit (regardless of any other chosen options).

.SH EXAMPLES
.LP
Format 3rd partition on 2nd hard disk with the volume label "JFS_hdb3":
.IP
.B jfs_mkfs -L JFS_hdb3 /dev/hdb3
.IP
.LP
Format 5th partition on 1st hard disk, verifying each block created:
.IP
.B jfs_mkfs -c /dev/hda5
.IP
.LP
Format 3rd partition on 2nd hard disk as external journal, format 4th
partition on 1st hard disk as JFS file system, and attach the external
journal to the file system:
.IP
.B jfs_mkfs -j /dev/hdb3 /dev/hda4
.IP

.SH "REPORTING BUGS"
.PP
If you find a bug in
.B JFS
or
.BR jfs_mkfs ,
please report it via the bug tracking system ("Report Bugs" section) of the JFS project web site:
.nf
http://jfs.sourceforge.net/
.fi
.PP
Please send as much pertinent information as possible including any error messages resulting from running
.BR jfs_mkfs .

.SH SEE ALSO
.BR mkfs (8) ,
.BR jfs_fsck (8) ,
.BR jfs_fscklog (8) ,
.BR jfs_tune (8) ,
.BR jfs_logdump (8) ,
.BR jfs_debugfs (8)


.SH AUTHORS
.nf
Barry Arndt  (barndt@us.ibm.com)
William Braswell, Jr.

.fi
.B jfs_mkfs
is maintained by IBM.
.nf
See the JFS project web site for more details:
http://jfs.sourceforge.net/
.fi