proc_scsi(5)

✨ NAME ✨

/proc/scsi/ — it's giving SCSI 💅

okay bestie, so this is proc_scsi, from section 5 of the File Formats Manual — the file formats girlies. buckle up 🎀

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🦋 DESCRIPTION 🦋

/proc/scsi/

so this is a whole directory, right? and inside it lives the scsi mid-level pseudo-file plus a bunch of SCSI low-level driver directories. each of those driver dirs has a file for every SCSI host on your system, and every single one of those files tells you the status of some lil part of the SCSI IO subsystem. 🌸

the files are full of ASCII structures, which means — bestie, this is the best part — you can just read them with cat(1). no fancy tools needed. iconic.

and if reading isn't enough for you? you can also write to some of these files to reconfigure the subsystem or switch certain features on or off. main character energy fr fr 👑

/proc/scsi/scsi

this one is a listing of all SCSI devices known to the kernel, and ngl it looks a lot like the listing you see during bootup. it's giving "greatest hits" 🎶

scsi currently supports only one command: add-single-device. that one lets root add a hotplugged device to the list of known devices. slay.

the command goes like this:

echo 'scsi add-single-device 1 0 5 0' > /proc/scsi/scsi

what that does ✨: it makes host scsi1 scan on SCSI channel 0 for a device on ID 5 LUN 0. cute, right?

🚨 but listen: if there's already a device known on this address, or if the address is just invalid, an error will be returned. no cap. so check yourself before you wreck yourself, bestie.

/proc/scsi/drivername/

so drivername can currently be any of these babies:

• NCR53c7xx
• aha152x
• aha1542
• aha1740
• aic7xxx
• buslogic
• eata_dma
• eata_pio
• fdomain
• in2000
• pas16
• qlogic
• scsi_debug
• seagate
• t128
• u15-24f
• ultrastore
• wd7000

these directories show up for all drivers that registered at least one SCSI HBA. every directory contains one file per registered host, and every host-file gets named after the number the host was assigned during initialization. it's giving assigned-seating-at-a-wedding 💐

reading these files will usually show driver and host configuration, statistics, and so on. the lore is all there 📖

writing to these files does different things on different hosts. for example:

• with the latency and nolatency commands, root can switch on and off the command latency measurement code in the eata_dma driver. toggle toggle 🔁
• with the lockup and unlock commands, root can control bus lockups simulated by the scsi_debug driver. simulation vibes 🧪

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🌈 SEE ALSO 🌈

• proc(5)

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and that's the whole page, bestie!! 🫶 this was proc_scsi(5) from Linux man-pages 6.20, dated 2026-02-08 — write that down, cite it in your essay, put it on a shirt, whatever. periodt. 💖✨