BLOGD(8)

BLOGD(8) — boot logging on /dev/console 💖

okay so bestie, welcome to the BLOGD(8) page, straight outta The SUSE boot concept ✨ this is the one about making your boot messages not just scroll past into the void 🫶

---

🌸 SYNOPSIS 🌸

/sbin/blogd [-f]

that's it. that's the whole vibe check 💅

---

🎀 DESCRIPTION 🎀

okay so here's the tea, <pink>blogd</pink> is a daemon and what it does first is figure out the real underlying character device behind /dev/console 👑

then it spawns a pty/tty pair and reconnects the current /dev/console with the slave of that pty/tty pair. no cap, that's the plan 🔥

and while it's writing information from this slave over to the real character device, it uses a ring buffer to hold that information so it can also write it to an existing logging file. icon behavior, honestly 🍓

if you wanna fetch the real tty of /dev/console, the program showconsole(8) can do that for you. and the advantage of doing it that way? blogd will not hold the real character device of /dev/console as its controlling tty — which matters because that would hangup any running getty on that character device 😭 and we do not want that.

---

✨ OPTIONS ✨

• -f — this one is for shutdown bestie, meaning reboot, halt, and poweroff, but also for kexec 💀 use it when things are going down.

---

🦋 BOOT PARAMETERS 🦋

blogd evaluates the following kernel command line parameters, periodt:

• blog.silent[=1|on|yes|true] — if set, all output to the underlying character devices is suppressed. super useful for preventing the console from getting flooded with messages 🌊 like, we get it, chill.
• blog.coldboot[=1|on|yes|true] — if set, it explicitly enables the early coldstart scan for systemd password requests (e.g. for LUKS decryption) during the initrd phase 🔐 lowkey important.
• blog.timeout=<integer> — on s390x (64-bit IBM System/390) and z/Architecture this specifies the timeout for the MORE prompt on the 3215 console. and if you set it to 0, the boot process does not need manual support 🎀 hands off, she's got it.

---

💜 SIGNALS 💜

blogd knows a few signals to control its behavior, bestie. here's the whole roster:

• SIGQUIT, SIGINT, and SIGTERM — these will cause blogd to try to write out the ring buffer and then exit 💅 clean getaway.
• SIGIO — tells blogd that it's now able to write on /var/log/boot.log, which means the file system is mounted read/write and the kernel messages are written to that file 🗂️ and after a reboot, the file /var/log/boot.old may exist where the former messages can be found — including the messages at shutdown up to the point where the file systems become unmounted 👑
• SIGSYS — tells blogd that it should stop writing to disk but continue to repeat messages to the old devices of the system console 🔁 still showing up, just not journaling.

---

🙈 BUGS 🙈

ngl, blogd needs a mounted /proc and /dev/pts file system — non-negotiable 🫶

it also tries to set the controlling tty to stdin if the real character device of /dev/console is not given. and after reading /proc, blogd tries to restore the status of the controlling tty to avoid problems with getty processes 😭

and yeah — this can fail, because blogd forks to run in the background as a daemon 💀 so, like, it's a known thing, not a skill issue on your end.

---

🧚 FILES 🧚

• /proc/<pid of blogd>/stat — the stat file of the blogd process 📊
• /dev/console — the system console 🖥️
• /var/log/boot.log, /var/log/boot.old — logging file which is created by blogd(8) 📝

---

🌈 SEE ALSO 🌈

showconsole(8), syslogd(8), proc(5) — go read these too, iykyk 📚✨

---

👑 COPYRIGHT 👑

2000,2015 Werner Fink, 2000 SuSE GmbH Nuernberg, Germany, 2015 SuSE Linux GmbH, 2026 SUSE Software Solutions Germany GmbH.

---

⭐ AUTHOR ⭐

Werner Fink <werner@suse.de>

---

and that's the whole page, bestie 🎀 main character energy from top to bottom — this one's from 3rd Berkeley Distribution and it's dated Jul 02, 2026. slay, go fix your boot logging 💖🦋