LFS-HEAT(1)

💖 LFS-HEAT(1) — bestie's guide to file heat 💖

okay so this is LFS-HEAT(1), from the Lustre User Utilities manual set, and we're gonna talk about file heat. yes. heat. like temperature but for your files. slay.

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✨ NAME ✨

lfs-heat_get, lfs-heat_set — the two commands you use to vibe with the file heat features 🦋

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🌸 SYNOPSIS 🌸

lfs heat_get FILE...
lfs heat_set [--help|-h] [--clear|-c] [--on|-O] [--off|-o] FILE...

like. that's it. that's the whole vibe. FILE... means you can hand it a whole little list of files, we love a command that takes a crowd 💅

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🎀 DESCRIPTION 🎀

so these are a set of lfs commands for interacting with the Lustre file heat feature. iconic.

now here's the tea, and it's important tea, no cap: file heat is only stored in memory with the file inode. meaning it might get reset to zero at literally any time, whenever the inode gets released because of memory reclaim. so don't treat it like a permanent record bestie, it's giving vibes, ephemeral. 😭

• lfs heat_get — gets the file heat for the files in your list 🫶
• lfs heat_set — sets heat flags on the files in your list ✨

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💅 OPTIONS 💅

• -c, --clear — clear the file heat on the files you gave it. bye bye heat 🧹
• -h, --help — print the usage message. the classic cry for help, we all need it sometimes 🙈
• -o, --off — turn file heat off on the given files
• -O, --on — turn file heat on on the given files 👑

okay bestie notice how -o is lowercase and -O is uppercase and they do the exact opposite things?? case matters. do not get cute with it. ⭐

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🌈 EXAMPLES 🌈

turn on file heat support for the whole Lustre filesystem:

# lctl set_param llite.$FSNAME*.file_heat=1

turn it off for the whole Lustre filesystem:

# lctl set_param llite.$FSNAME*.file_heat=0

display the current file heat for foo:

# lfs heat_get /mnt/lustre/foo
flags: 0

readsample: 0
writesample: 16
readbyte: 0
writebyte: 16777216

look at those numbers go. writebyte: 16777216. she's been writing. 📝

clear the file heat for foo:

# lfs heat_set -c /mnt/lustre/foo

turn off file heat for foo:

# lfs heat_set -o /mnt/lustre/foo

turn on file heat for foo:

# lfs heat_set -O /mnt/lustre/foo

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⭐ AVAILABILITY ⭐

the lfs heat_get and lfs heat_set commands are part of the lustre(7) filesystem package, and they've been in there since release 2.13.0 🎀 so if you're on something older... bestie. upgrade. 💀

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🦋 SEE ALSO 🦋

• lfs(1)
• lustre(7)

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and that's the whole page!! this was LFS-HEAT(1) from Lustre, dated 2024-08-30 💖 go forth and check ur file heat, ily, periodt 🌸✨🫶