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jfs_tune(8) [centos man page]

jfs_tune(8)						  Set JFS file system parameters.					       jfs_tune(8)

NAME
jfs_tune - adjust tunable file system parameters on JFS SYNOPSIS
jfs_tune [options] device DESCRIPTION
jfs_tune adjusts tunable parameters on a Linux JFS file system or external journal. jfs_tune must be run as root. device is the special file name corresponding to the actual device (e.g. /dev/hdb1) on which a JFS file system or JFS external journal has been created. OPTIONS
-J device=external-journal Attach the JFS external journal located on external-journal to the JFS file system on device. The external journal must already have been created using the command. More than one file system may share the same external jour- nal. mkfs.jfs -J journal_dev external-journal Attach the external journal to the file system by using the command jfs_tune -J device=external-journal device Instead of specifying a device name directly, external-journal can also be specified by either LABEL=label or UUID=UUID (Use jfs_tune -l device to display a journal device's volume label and UUID.) -l List the contents of the JFS file system or external journal superblock that resides on device. -L volume-label Set the volume label of the JFS file system or external journal. JFS labels can be at most 16 characters long; if volume-label is longer than 16 characters, jfs_tune will truncate it and print a warning. The volume label can be used by mount(8), fsck(8), and /etc/fstab(5) (and possibly others) by specifying LABEL=volume_label instead of a block special device name like /dev/hda5. -U UUID Set the universally unique identifier (UUID) of the file system or external journal device to UUID. The format of the UUID is a series of hex digits separated by hyphens, like this: "c1b9d5a2-f162-11cf-9ece-0020afc76f16". The UUID parameter may also be one of the following: clear clear the file system UUID random generate a new randomly-generated UUID time generate a new time-based UUID The UUID may be used by mount(8), fsck(8), and /etc/fstab(5) (and possibly others) by specifying UUID=uuid instead of a block spe- cial device name like /dev/hda1. See uuidgen(8) for more information. -V Print version information and exit (regardless of any other chosen options). EXAMPLES
Set a randomly-generated UUID for the JFS file system on the 3rd partition of the 2nd hard disk, and view the resultant superblock: jfs_tune -l -U random /dev/hdb3 Attach an already existing external journal on a device labeled JFSLog to a JFS file system on /dev/hda8: jfs_tune -J device=LABEL=JFSLog /dev/hda8 REPORTING BUGS
If you find a bug in JFS or jfs_tune, please report it via the bug tracking system ("Report Bugs" section) of the JFS project web site: http://jfs.sourceforge.net/ Please send as much pertinent information as possible including any error messages resulting from running jfs_tune. SEE ALSO
jfs_fsck(8), jfs_mkfs(8), jfs_fscklog(8), jfs_logdump(8), jfs_debugfs(8) AUTHOR
Barry Arndt (barndt@us.ibm.com) jfs_tune is maintained by IBM. See the JFS project web site for more details: http://jfs.sourceforge.net/ October 28, 2002 jfs_tune(8)

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jfs_mkfs(8)						     JFS file system creation						       jfs_mkfs(8)

NAME
jfs_mkfs - create a JFS formatted partition SYNOPSIS
jfs_mkfs [options] device [ blocks ] DESCRIPTION
jfs_mkfs is used to create (format) a JFS partition. jfs_mkfs must be run as root. device is the special file name corresponding to the actual device (e.g. /dev/hdb1) on which a JFS file system and/or JFS journal will be created. blocks is the number of blocks to be used for the file system. If omitted, jfs_mkfs automatically figures the file system size. The default block size is 4096. WARNING
jfs_mkfs will destroy all data on the specified device! OPTIONS
-c Check the device for bad blocks before building the file system. -j journal_device Create the external JFS journal on journal_device , create the JFS file system on device , and attach the external journal to the file system. -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: journal_dev Create an external JFS journal on the given device. device=external-journal Attach an existing external JFS journal located on external-journal to the JFS file system that will be created on device. The external journal must already have been created using the command jfs_mkfs -J journal_dev external-journal Attach the external journal to the file system being created by using the command jfs_mkfs -J device=external-journal device Instead of specifying a device name directly, external-journal can also be specified by either LABEL=label or 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 jfs_tune(8) to display a journal device's volume label and UUID. (See the -l, -L, and -U options of jfs_tune(8).) Only one of the journal_dev or device= options can be given per jfs_mkfs issuance. -L volume_label Set the volume label for the newly formatted device. If -L volume_label is used along with -J journal_device, the volume label of the specified external journal device will be set to volume_label. Otherwise, the volume label of the JFS file system will be set to volume_label. -O Provide case-insensitive support for compatibility with OS/2. -q Quiet execution - do not ask for confirmation before creating the file system. -s log_size Set the log size (in megabytes) of the inline log. If the -s option is not used, the default log size is 0.4% of the aggregate size. -V Print version information and exit (regardless of any other chosen options). EXAMPLES
Format 3rd partition on 2nd hard disk with the volume label "JFS_hdb3": jfs_mkfs -L JFS_hdb3 /dev/hdb3 Format 5th partition on 1st hard disk, verifying each block created: jfs_mkfs -c /dev/hda5 Format 3rd partition on 2nd hard disk as external journal, format 4th partition on 1st hard disk as JFS file system, and attach the exter- nal journal to the file system: jfs_mkfs -j /dev/hdb3 /dev/hda4 REPORTING BUGS
If you find a bug in JFS or jfs_mkfs, please report it via the bug tracking system ("Report Bugs" section) of the JFS project web site: http://jfs.sourceforge.net/ Please send as much pertinent information as possible including any error messages resulting from running jfs_mkfs. SEE ALSO
mkfs(8), jfs_fsck(8), jfs_fscklog(8), jfs_tune(8), jfs_logdump(8), jfs_debugfs(8) AUTHORS
Barry Arndt (barndt@us.ibm.com) William Braswell, Jr. jfs_mkfs is maintained by IBM. See the JFS project web site for more details: http://jfs.sourceforge.net/ March 9, 2005 jfs_mkfs(8)

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