Booting Linux in few secs, suggestions welcomed

ben

As many of you I've been really impressed by Arjan van de Ven and his colleagues when after the Plumbers Conference (I wish to see it... sigh) he posted an impressive presentation with a "live demo" of a complete system booting in 5 secs.

I know: they've targeted a designed machine, SSD disks and an internal support from Intel for beeing able do work on that. I'm trying to find docs and real case studies for a LSB distro capable of booting in few secs with common SATA (not SSD) disks on a more common and affordable hardware. I'd like to port a media center and I wish to have it running under X in few secs instead of waiting for more than 20 secs.

I've obtained nice results by customizing stock distros (Gentoo, Slack, Debian) but I've never been able to have X fully running under 15-20 secs. It would be great to share your impressions, patches, tips for your favorite distro; best performances will go to Gentoo (parallel init makes me boost) and Slackware at the moment, I've not tried to "return back" to LFS for this task but I'll do it if patches and improvements will make the difference.

Note to moderators: I don't know the right place where I can put this strange argument, please move it if not appropriate (I don't love to double/triple/.. post in every distro forum)

Ben

mfillpot

I have been quite happy with my 20 second boot time on slackware running the generic kernel, the only recommendation that I have are to watch the services and startup scripts and limit any functions that you do not actually need to run at each boot.

I think your best option would be to build a custom kernel with built in support for your necessary hardware rather than all hardware, this should help to reduce some of the lag.

As for the location, I believe you are watching the boot scripts and that the kernel would be the only option left for you, so this is a perfect location.

ben

Thanks Matt,
I've had same performances with my hardware, no SSD involved.
With Gentoo I've obviously compiled the kernel on my own because it's a part of the installation process, I've removed modules everywhere and I'm now using only support for the specific hw (Intel SATA controller, NVidia GPU, ...).
In my init scripts I've even delayed services like networking and started X before everything else but it's quite hard to get better results. I've even tried to improve boot speed with readahead but I've not optimized so much.
It seems I can achieve better results with standby/resume but I'm still studying kernel opts and readahead to get something more, is there anyone experienced with it ?

Ben

woboyle

I run Debian Edge on an ARM board that boots in 1.5 seconds from SD card or flash memory, or 4.5 seconds when mounting the root file system (/) from a remote NFS share. What takes so long for most systems is that they are running a lot of services and drivers that are not needed for the hardware or system in question. This is why manually configured and source-built distributions such as Gentoo boot a lot quicker than ones which have the entire kitchen (sink, dishwasher, stove, microwave, and coffee maker) built into them (name your distribution).

ben

As many of you I prefer to stay with distros like Gentoo or Slackware (wish to have enough time to use LFS but...), but even Debian performs well when properly configured. It seems there're troubles with x86 machines hardware (starting from bios, sata, ...) so you cannot go under certain performances. Don't know if Arjan Van De Ven used customized bioses (even if he's worked for Intel and even on splashtop and that kind of things) and if SSDs really affect performances but I guess so.

@Rubberman
What kind of hw are you using ? I'm interested in it. I'm dealing with custom embedded devices (MIPS architecture) but I don't have video output (HDMI, VGA, ...) and I'm returning back to x86 machines because they're cheap and affordable for a media center

woboyle

@Andrea
It will be a week or so before I get back to this. I'm on a trip right now and quite tied up w/ family stuff. I've been using ARM hardware, which has some video support. Usually for that I set the DISPLAY environment to point to my workstation when I want to run X11 applications on the board. Anyway, when I have some time, I'll try to point you to some hardware that will do what you need. FWIW, I have found embedded ARM boards considerably less expensive than x86 boards. Don't know about MIPS hardware since the only things I have worked with other than workstations for those are some router devices.

ben

I guess ARM is the way to go, I've tried to optimize everything on a common x86 machine but I've a lot of troubles: from BIOS to Sata Hard Disks (except SSD...)