FS_PRECACHE(1)

✨ FS_PRECACHE(1) — the AFS Command Reference glow-up ✨

okay bestie, so this is fs_precache from the AFS Command Reference, and it's genuinely one of those little commands that just... quietly makes things better. no cap. let's get into it 💅

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🌸 NAME 🌸

fs_precache — sets the precache size, periodt.

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🎀 SYNOPSIS 🎀

fs precache -blocks <size in 1K blocks>
    [-help]

fs p -b <size in 1K blocks>
    [-h]

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🦋 DESCRIPTION 🦋

so here's the vibe: fs precache tells the Cache Manager how hard it should try to prefetch cache blocks when some app opens a file for reading. 🫶

if you turn this behavior on, then the moment a file gets opened for reading, the Cache Manager immediately kicks off an asynchronous fetch request for that file. that fetch grabs the amount of data you configured and stashes it in the cache. in some scenarios this can improve performance — it's giving ✨ main character optimization energy ✨.

lowkey important note: this prefetching is done by the Cache Manager itself. the underlying Operating System may also be out here doing its own prefetching behavior, depending on various settings or application hints. so like, two different girlies can be prefetching at the same time, iykyk.

this command was introduced in OpenAFS 1.5.37. throwback era 🕰️

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💖 OPTIONS 💖

• -blocks <size in 1K blocks> — specifies how much data to prefetch for each applicable file, measured in 1024-byte blocks. specify 0 to disable prefetching behavior. by default, prefetching is disabled. (so yeah, the default is off, bestie — you gotta opt in 💅)
• -help — prints the online help for this command. all other valid options are ignored. she said "I'm the main character now" 😭

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🌈 OUTPUT 🌈

if the precache size you specified got set successfully, you'll see this message print out:

New precache size set.

slay. that's the whole notification. ✨

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🍓 EXAMPLES 🍓

this command configures the Cache Manager to prefetch the first 100 kilobytes of any file that's opened for reading:

% fs precache -blocks 100
New precache size set.

look at her go 👑

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👑 PRIVILEGE REQUIRED 👑

the issuer must be logged in as the local superuser root. no random account energy here — you need the big one. 🔥

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🧚 SEE ALSO 🧚

• afsd(8)

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💜 COPYRIGHT 💜

Copyright 2013 Sine Nomine Associates

This documentation is covered by the BSD License as written in the doc/LICENSE file. This man page was written by Andrew Deason for OpenAFS.

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fr fr, that's the whole page. nothing skipped, nothing invented, all facts intact. 💀

and that's a wrap! this page is from OpenAFS, dated 2026-07-27 — go forth and precache responsibly, bestie 🦋💖