jfs_fsck(8)

💖 jfs_fsck — bestie edition 💖

okay so real talk: jfs_fsck is the JFS utility that does file system check. it's a section 8 manual page, aka system administration land, aka you need root for this, no cap. let's get into it 🫶

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✨ NAME ✨

jfs_fsck — initiate replay of the JFS transaction log, and check and repair a JFS formatted device

she does three things and she does them fabulously: replay the log, check the device, fix what's broken. 💅

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🌸 SYNOPSIS 🌸

jfs_fsck [ -afnpvV ] [ -j journal_device ] [ --omit_journal_replay ] [
--replay_journal_only ] device

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🦋 DESCRIPTION 🦋

so jfs_fsck is used to replay the JFS transaction log, check a JFS formatted device for errors, and fix any errors found. that's the whole job description and honestly? iconic.

device is the special file name corresponding to the actual device to be checked (e.g. /dev/hdb1). like, the real physical thing, bestie, not a vibe.

jfs_fsck must be run as root. no exceptions, no "but i have sudo at home", just root. periodt.

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⚠️ WARNING ⚠️ (read this one fr fr)

jfs_fsck should only be used to check an unmounted file system or a file system that is mounted READ ONLY. using jfs_fsck to check a file system mounted other than READ ONLY could seriously damage the file system! like, not a little damage. seriously damage. i am begging you. unmount first. 🙈

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👑 OPTIONS 👑

if no options are selected, the default is -p. she'll just preen, it's fine.

• -a — Autocheck mode. Replay the transaction log. Do not continue fsck processing unless the aggregate state is dirty or the log replay failed. Functionally equivalent to -p. Autocheck mode is typically the default mode used when jfs_fsck is called at boot time.
• -f — Replay the transaction log and force checking even if the file system appears clean. Repair all problems automatically. she does NOT care that it looks fine, she's checking anyway 🔥
• -j journal_device — Specify the journal device. you're telling her where the journal lives.
• -n — Open the file system read only. Do not replay the transaction log. Report errors, but do not repair them. look-only mode, hands off 🎀
• --omit_journal_replay — Omit the replay of the transaction log. This option should not be used unless as a last resort (i.e. the log has been severely corrupted and replaying it causes further problems). last resort ONLY, i'm so serious.
• -p — Automatically repair ("preen") the file system. Replay the transaction log. Do not continue fsck processing unless the aggregate state is dirty or the log replay failed. Functionally equivalent to -a. the default bestie ✨
• --replay_journal_only — Only replay the transaction log. Do not continue with a full file system check if the replay fails or if the file system is still dirty even after a journal replay. In general, this option should only be used for debugging purposes as it could leave the file system in an unmountable state. This option cannot be used with -f, -n, or --omit_journal_replay. debugging only, and she has RULES about who she'll hang out with.
• -v — Verbose messaging. print details and debug statements to stdout. she's telling you everything, and honestly good for her 💜
• -V — Print version information and exit (regardless of any other chosen options). she said bye, nothing else matters 🌈

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🍓 EXAMPLES 🍓

check the 3rd partition on the 2nd hard disk, print extended information to stdout, replay the transaction log, force complete jfs_fsck checking, and give permission to repair all errors:

jfs_fsck -v -f /dev/hdb3

check the 5th partition on the 1st hard disk, and report, but do not repair, any errors:

jfs_fsck -n /dev/hda5

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💀 EXIT CODE 💀

the exit code returned by jfs_fsck represents one of the following conditions:

• 0 — No errors. immaculate. no notes. 🌸
• 1 — File system errors corrected and/or transaction log replayed successfully
• 2 — File system errors corrected, system should be rebooted if file system was mounted
• 4 — File system errors left uncorrected 😭
• 8 — Operational error
• 16 — Usage or syntax error
• 128 — Shared library error

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🧚 REPORTING BUGS 🧚

if you find a bug in JFS or jfs_fsck, 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 the complete output of running jfs_fsck with the -v option on the JFS device. the -v receipts, bestie, we need them 📝

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🎀 SEE ALSO 🎀

fsck(8), jfs_mkfs(8), jfs_fscklog(8), jfs_tune(8), jfs_logdump(8), jfs_debugfs(8)

the whole friend group honestly, go say hi 🫶

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💅 AUTHORS 💅

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

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

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okay that's the whole page, you ate it, go unmount your filesystem before you run anything 💖

this page is from October 29, 2002, and it lives in section 8 of the manual — jfs_fsck(8), forever and always, slay ✨👑