FSTRACE_SETLOG(8)

💖 FSTRACE_SETLOG 💖 (that's fstrace_setlog from the FSTRACE_SETLOG(8) manual, bestie)

okay so. you wanna resize a trace log. that's it, that's the whole vibe. sit down, hydrate, let's go 🫶

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✨ NAME ✨

fstrace_setlog — sets the size of a trace log. literally just resizing a thing. iconic behavior honestly 👑

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🌸 SYNOPSIS 🌸

fstrace setlog [-log <log name>+]
    -buffersize <1-kilobyte units> [-help]

fstrace setl [-l <log name>+]
    -b <1-kilobyte units> [-h]

so there's a long form and a short form and they do the exact same thing, pick your fighter 💅

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🦋 DESCRIPTION 🦋

okay so the fstrace setlog command defines how many kilobytes of kernel memory get allocated for the "cmfx" trace log. like you're telling the kernel "hey bestie, this is how much room you're getting" 🎀

and here's the part where it gets a little dramatic: if kernel memory is currently allocated, the command clears the current log and creates a brand new log buffer of the size you specified. so yeah. it's giving "no thoughts, fresh start." your old log? gone. not me doing a hard reset 😭

wanna see the currently defined size of the log buffer? run the fstrace lslog command with the -long argument. and if you wanna control whether that indicated amount of space is actually allocated, use the fstrace setset command to set the status of the "cm" event set. to peek at the event set's status, hit up the fstrace lsset command. it's a whole little ecosystem, iykyk ✨

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💅 OPTIONS 💅

• -log <log name>+ — names the trace log you're setting the size for. the only acceptable value is "cmfx", which is also the default if you just... don't say anything. valid. go off. 🌈
• -buffersize <1-kilobyte units> — specifies the number of 1-kilobyte blocks of kernel memory to allocate for the trace log. so like, do the math on your units, okay?? 🙈
• -help — prints the online help for this command. and here's the tea: all other valid options are ignored. so don't sneak them in thinking they'll do something 💀

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🍓 EXAMPLES 🍓

the following command allocated 80 KB of kernel memory for the "cmfx" trace log:

# fstrace setlog -log cmfx -buffersize 80

80 KB!! allocated!! slay 🔥

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👑 PRIVILEGE REQUIRED 👑

the issuer must be logged in as the local superuser root. no root, no resize, no exceptions bestie, that's the rule <3

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🔥 SEE ALSO 🔥

fstrace(8), fstrace_lslog(8), fstrace_lsset(8), fstrace_setset(8)

go read those too, they're in the same friend group 🫶

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🎀 COPYRIGHT 🎀

IBM Corporation 2000. http://www.ibm.com/ All Rights Reserved.

This documentation is covered by the IBM Public License Version 1.0. It was converted from HTML to POD by software written by Chas Williams and Russ Allbery, based on work by Alf Wachsmann and Elizabeth Cassell.

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okay that's the whole page!! 💜 this was brought to you by OpenAFS, dated 2026-07-27, and yes i read the entire thing so you don't have to. go resize a trace log, you main character 🧚✨