SG_REP_DENSITY(8)

💖 SG_REP_DENSITY(8) 💖

Part of the sg3_utils crew, so you know it's serious 🧚

✨ NAME ✨

okay so sg_rep_density is the tool that sends a SCSI REPORT DENSITY SUPPORT command 📼 it's giving tape drive energy, literally.

🎀 SYNOPSIS 🎀

sg_rep_density [--help] [--hex] [--inhex=FN] [--maxlen=LEN] [--media]
[--raw] [--readonly] [--typem] [--verbose] [--version] DEVICE

🦋 DESCRIPTION 🦋

bestie, this one sends a SCSI REPORT DENSITY command to DEVICE and then prints whatever comes back 💅 it's tape drive specific, so don't expect it to vibe with your SSD 💀 The command shows up in the SSC-5 draft standard, revision 6 (ssc5r06.pdf), and it was already around back in the SSC-2 standard (ANSI INCITS 380-2003) ✨

by default it asks the DEVICE (like a tape drive) for its density code descriptors and then decodes the answer 🔥 if you throw in --typem, it goes for the medium type descriptors instead 🌸 and with --media, it checks what the density codes or medium type descriptors are for the media sitting inside the DEVICE (like a tape cartridge) 🫶

👑 OPTIONS 👑

Arguments to long options are mandatory for short options as well, so don't get lazy about it 🙈

• -h, --help — shows you the usage message, then bounces 👋
• -H, --hex — dumps the response as hexadecimal to stdout 🍓 one use gives you the whole thing in ASCII hex with an address on each line, starting at 0 🧚 two uses gives you hex with no leading address on each line 🌈 three uses gives you output you can save to a file and feed back into another run with --inhex=FN 💜
• -i, --inhex=FN — FN is a file whose contents are treated as ASCII hexadecimal ✨ if you also give DEVICE, it gets ignored and you'll get a warning, but the tool keeps going and decodes the file FN 🥺 check the "HEX, BINARY AND JSON FORMATS" section in the sg3_utils manpage for more deets 📖 and if you add --raw too, then FN is treated as binary instead 🤖
• -m, --maxlen=LEN — LEN is the (maximum) response length in bytes 🌸 it goes into the cdb's "allocation length" field 💅 if you don't give it, or LEN is zero, the default is 8192 ✨ the biggest LEN you can use is 65535 🫶
• -M, --media — flips the MEDIA bit in the cdb, so the density codes (or medium types) that the tape cartridge in the drive supports get included in the response 📼 by default you get the codes the tape drive itself supports 🎀 heads up: if there's no "medium" (like a tape cartridge) in the drive, the SCSI command will fail with a "not ready" sense key 😭
• -r, --raw — outputs the SCSI response (the data-out buffer) as binary to stdout 🦋 unless you're using --inhex=FN 🙈 when you pair it with --inhex=FN, the contents of FN get read as binary rather than hex 💜
• -R, --readonly — opens the DEVICE read-only, like using the O_RDONLY flag on Unix 🔒 the default is read-write 🌈
• -t, --typem — flips the MEDIUM TYPE bit in the cdb, so you get the medium types supported by the tape drive (or tape cartridge) in the response 🧚 without it, you get density codes 🍓
• -v, --verbose — cranks up the verbosity so you get more debug output 🔥
• -V, --version — prints the version string, then peaces out ✌️

🌸 EXIT STATUS 🌸

when everything goes right, sg_rep_density exits with 0 ✨ if it doesn't, check the sg3_utils(8) man page for the full story 💀

🫶 AUTHORS 🫶

Written by Douglas Gilbert, the legend himself 👑

🙈 REPORTING BUGS 🙈

if something's broken, send the bug report to <dgilbert at interlog dot com> 💌

🌈 COPYRIGHT 🌈

Copyright © 2022-2023 Douglas Gilbert 💖 This software is distributed under a BSD-2-Clause license. There is NO warranty, not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE 😭

🧚 SEE ALSO 🧚

sg3_utils(sg3_utils) 💜

okay bestie, that's the whole tea ☕ this page came from sg3_utils-1.48, dated June 2023, and it's still giving 👑🎀✨