jfs_mkfs(8)

🦋 NAME 🦋

ok so bestie, meet jfs_mkfs — the icon, the moment, the tool that creates a JFS formatted partition. it's from the jfs_mkfs(8) manual, and she's here to make your disk beautiful (after obliterating literally everything on it, but we'll get to that 💀).

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✨ SYNOPSIS ✨

jfs_mkfs [options] device [ blocks ]

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🌸 DESCRIPTION 🌸

jfs_mkfs is the girl who creates (formats) a JFS partition. and no cap, she has one requirement: you must run her as root. like, root. she does not play.

device is the special file name that points at the actual device (think /dev/hdb1) where your JFS file system and/or JFS journal is gonna live. blocks is how many blocks you want the file system to use. leave it out and jfs_mkfs just figures the file system size herself. main character energy, honestly.

the default block size is 4096. periodt.

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🚨 WARNING 🚨

jfs_mkfs will destroy all data on the specified device!

not exaggerating. not being dramatic. everything. gone. bye. 🪦 so please, for the love of everything, double-check that device name before you hit enter.

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💅 OPTIONS 💅

• -c — check the device for bad blocks before building the file system. a little pre-flight vibe check. 🩺
• -j journal_device — create the external JFS journal on journal_device, create the JFS file system on device, and attach that 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 whatever options you throw on the command line. here's what's supported:
  • journal_dev — create an external JFS journal on the given device. ✨
  • device= external-journal — attach an existing external JFS journal living on external-journal to the JFS file system that's about to be created on device. that external journal has to already exist, and you make it with:

jfs_mkfs -J journal_dev external-journal

then you attach that external journal to the file system you're creating with:

jfs_mkfs -J device=external-journal device

and listen — instead of naming a device directly, external-journal can also be given as either LABEL=label or UUID=UUID, so it finds the external journal by its volume label or UUID stored in the JFS external log superblock at the start of the journal. use jfs_tune(8) to show a journal device's volume label and UUID. (peep the -l, -L, and -U options of jfs_tune(8).) 👀

heads up bestie: only one of journal_dev or device= can be given per jfs_mkfs issuance. pick a lane. 🛑

• -L volume_label — set the volume label for the newly formatted device. and if you use -L volume_label together with -J journal_device, then the volume label of that specified external journal device gets set to volume_label. otherwise, the volume label of the JFS file system gets set to volume_label. 🏷️
• -O — provide case-insensitive support for compatibility with OS/2. retro moment. 🕰️
• -q — quiet execution. do not ask for confirmation before creating the file system. no questions, just vibes. 🤫
• -s log_size — set the log size (in megabytes) of the inline log. if you don't use -s, the default log size is 0.4% of the aggregate size. 📏
• -V — print version information and exit. and she means exit regardless of any other chosen options. like, she's leaving, don't try to stop her. 👋

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🌈 EXAMPLES 🌈

format the 3rd partition on the 2nd hard disk with the volume label "JFS_hdb3":

jfs_mkfs -L JFS_hdb3 /dev/hdb3

format the 5th partition on the 1st hard disk, verifying each block created:

jfs_mkfs -c /dev/hda5

format the 3rd partition on the 2nd hard disk as an external journal, format the 4th partition on the 1st hard disk as a JFS file system, and attach that external journal to the file system:

jfs_mkfs -j /dev/hdb3 /dev/hda4

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🐛 REPORTING BUGS 🐛

if you find a bug in JFS or jfs_mkfs, pls report it via the bug tracking system (the "Report Bugs" section) of the JFS project web site:

http://jfs.sourceforge.net/

and send as much pertinent information as you possibly can, including any error messages that came out of running jfs_mkfs. the more tea, the better. 🫖

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👀 SEE ALSO 👀

mkfs(8), jfs_fsck(8), jfs_fscklog(8), jfs_tune(8), jfs_logdump(8), jfs_debugfs(8)

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👑 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/

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and that's the whole page, bestie!! 💖✨🎀 this one's dated March 9, 2005, and it's page jfs_mkfs(8) from the JFS file system creation manual — she's been serving since '05 and she's still iconic. go forth, format responsibly, and don't forget to check that device name twice 🦋💜