libnvme(2)

💖 libnvme(2) — your bestie's guide to struct nvme_mi_ctrl_health_status 💖

okay so we're doing a manual page from libnvme, section 2 (that's the API manual bestie, we're in the library zone not the command zone ✨), and today's main character is the Controller Health Data Structure, aka CHDS. yes it's an acronym. yes you should use it. it's giving "i check my own vitals and i'm thriving" 🩺💅

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🌸 NAME 🌸

struct nvme_mi_ctrl_health_status — the Controller Health Data Structure (CHDS) 🫶

literally it's the little struct that holds all the "how are we doing today, controller?" tea ☕✨

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🦋 SYNOPSIS 🦋

here's the whole thing, no cap, copy it exactly bestie:

struct nvme_mi_ctrl_health_status {
    __le16 ctlid;
    __le16 csts;
    __le16 ctemp;
    __u8 pdlu;
    __u8 spare;
    __u8 cwarn;
    __u8 rsvd9[7];
 };

yes those are __le16 and __u8 types — little-endian 16-bit and plain old 8-bit. the kernel devs said "we're being explicit about byte order" and honestly? slay, respect 🙌

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👑 Members 👑

okay so these are the fields, one by one, no skipping, i promised 🎀

• ctlid — Controller Identifier. it's the controller's lil name tag so you know which controller we're talking about 💖
• csts — Controller Status. the vibe check, in field form ✨
• ctemp — Composite Temperature. how hot is it running? is it overheating or is it fine? this field knows 🌡️🔥
• pdlu — Percentage Used. the percentage-used stat, out here reminding you that everything ages 😭
• spare — Available Spare. the spare capacity still kicking around, your safety net bestie 🫶
• cwarn — Critical Warning. the ⚠️ field. when this one's talking, you should probably be listening 👀💀
• rsvd9 — Reserved. do not touch. it's not for you. it's reserved, periodt 💅 (seriously, leave it alone, it's reserved)

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🌈 the cute sign-off 🌈

this page is from libnvme, section 2, and it's dated July 2026 — so yes, the future called and it still wants you to read your manual pages 📅💜

also quick reminder bestie: rsvd9 is Reserved. reserved means not yours. i'm not saying you'd poke it. i'm saying i know you were thinking about it. 🙈

bye mwah, go read more manpages, they're lowkey iconic 🧚‍♀️🎀✨