Cutting down bootup time (to 5 sec)

[VinzC]

Update

I tested one of my virtual machines, an LDAP/Kerberos server with no graphical interface at all, only Quingy. Boot time is 7.53 seconds according to /proc/uptime. It uses ReiserFS and I'm planning to switch to XFS soon.

I agree, this is no real-life test but I'm fairly pleased with such a low boot time. Features:

• Host CPU: Intel Core2 Duo T9400 @ 2.53GHz (ok, not quite everyones machine )
  
• Host kernel: 2.6.31-gentoo-r4
  
• Virtual disk: QCOW2, 6GB, 50% free
  
• Guest kernel: 2.6.27-gentoo-r8, unmodified
  
• Guest SMP: 2
  
• Guest system: Baselayout-2 and OpenRC-0.5.2-r2
  
• Virtio devices for block and network in KVM guest
  
• Text mode only
  
• Parallel startup (rc.conf)
  
• Gentoo stable branch only (except Baselayout, SysVinit and OpenRC)
  
• Custom network script library (not using OpenRC network scripts at all)
  
• Static IP address, no DHCP

I didn't use a recent kernel as I didn't want to recompile the whole toolchain (gcc-4.3 and glibc) hence I'm still with glibc-2.8* and gcc 4.1*. I might upgrade gcc (my KVM guest RAM is only 256MB and I need to give it more for GCC to compile... ), glibc and the kernel as well very soon.

Stay tuned for more tests.

EDIT: Now it's worth explaining the extremely low boot time is a warm boot time. Cold boot (on battery) averages 20 seconds. The difference is due to caching on the host side .

EDIT: With XFS on the root filesystem instead of Reiserfs boot time decreases to less than 6 seconds!... (Warm boot again.)
_________________
Gentoo addict: tomorrow I quit, I promise!... Just one more emerge...
1739!

[Etal]

[regomodo]

Try linux-2.6.32. I've noticed my boot time to drop noticeably on my laptop.

[Letharion]

[Xytovl]

There are some new things we can try : Ubuntu is aiming at reducing boot time, so they copy patches from moblin. We can probably do the same, here are the patches http://people.canonical.com/~sconklin/mobp/ and this is the thread about it : https://lists.ubuntu.com/archives/ubuntu-x/2009-December/000689.html
The info comes from phoronix, I'll give a try to the patches as soon as I have time.

[Xytovl]

I've just tested them, on an eeePC 901, except for 0003-drm-remove-root-requirement-from-DRM_IOCTL_SET_VERSI.patch that seems to be already applied on gentoo-sources-2.6.32 (or maybe something else I have used before ).
This works great ! bootchart says 13s to gdm (init starts 1.5 seconds earlier)
The other things I had to do to cut times a lot is to blacklist eeepc-laptop and rt2860pci modules, and add a modprobe & command in a newly created script. Is there a clean way to say that some mobules can be loaded in the background ? It takes about 2 seconds to load the modules but they are not needed for the boot process.

The last optimisation is very eee-specific, I have cut readahead-list into two parts : the first one is for the 4Gb SSD (the root filesystem) and is run at sysinit, the second one is for the second SSD and is run after localmount.

[shgadwa]

There's some things I've done thats reallly helped.

1. I upgraded to baselayout2 and openrc. It went really smooth and this has helped a lot.
2. I do parallel startups. Some say this is not good, but I've never seen a problem with it.
3. I use wicd so my network cards do not even have to start at boot.
4. I use slim as a lightweight login manager.
5. I upgraded to a 2.6.32 kernel. I used the zen-sources. I started "from seed" using the pappy's guide and I left everything that I did not need unchecked.
6. I added quiet fastboot to the kernel boot line in menu.lst

With the above optimizations, I'm at 23 secs. I would be nice if I could get it smaller than that. Maybe preload might help with starting X. Right now, preload does not even start. Don't know why. Sometimes it works and sometimes it don't.

I've tried to boot with or without a login manager and I get the same speed either way. For now, at least I got a decent improvement.

One thing I've tried that helps is to put xdm on the boot runlevel instead of the default runlevel. This only works sometimes though because often times it would cause X to freeze as soon as it loads to the login window.

Xytovl, do you have any idea how I could add these patches to the 2.6.32-zen3 kernel?

[Xytovl]

I have never used non gentoo-sources kernels, I imagine it works the same way and creates a directory in /usr/src. You just have to do int the kernel's directory

[VinzC]

[shgadwa]

[shgadwa]

Xytovl,

The link you gave for the kernel patch does not work. It looks like they must of moved it or deleted it. What is the patch called? Maybe I can find it elsewhere online.

[shgadwa]

I found this thread here and thought I would dig it out...

How is sreadahead working for you? I've got readahead installed right now. I've not tried it yet because I'm waiting for my system to finish compiling everything with the --as-needed LDFLAG.

Anyhow, there's also Upstart... but I have no idea if it will work on gentoo or not. Right now I boot up in 23 secs. It would be nice to shorten that. We will see what happens after my computer is finished compiling.

[Letharion]

As I recall I never noticed any difference, and by the time 29 was released and stable, I had forgotten about this.
I'm gonna give it a new go
Let me know what happens.

[Xytovl]

You're right, the patchs are not there anymore, the names are :

[shgadwa]

[shgadwa]

Great!

While you're at it, here's some things you can try:

1. Rebuild your system with the --as-needed LDFLAG. This is supposed to help a lot. It takes a while though. I'm still not finished rebuilding my system. I think it might be done by tomorrow morning.
2. Upgrade to Baselayout2 & OpenRC. It seems to me like the process is a lot easier now than it was a year ago. OpenRC is more stable too.
3. Experiment with using parallel startup and not using parallel startup. See what is better. I've not tried that yet either as I'm waiting for my system to be done compiling.
4. Type in rc-status and remove all that you no longer need.
5. Put xdm on the boot runlevel instead of the default runlevel. If this will work for you, it usually makes it faster. However, I've not been able to get it working because every time slim loads, it locks up. I'm guessing that maybe this is a slim problem and I just switched to gdm. Maybe that will help.
6. Use the fastboot kernel parameter. This does not make you bootup in 5 seconds, but it shaves a lot off the boot time.
7. Try patching the kernel. Here are some names of some patches:

[Shining Arcanine]

I read through this thread and it seems that no one mentioned setting RC_PARALLEL_STARTUP to yes in /etc/conf.d/rc. That should probably yield a decent speed improvement.

[regomodo]

[pianosaurus]

[Xytovl]

[shgadwa]

Well, The fastboot option is that one where you load the kernel with the "fastboot" option... making kernel loading very fast.

However, I'm starting to question this. I think that if I want my computer to bootup faster, I should probably seek out some other means. I mean, this disables fs check... isn't that potentially dangerous?

[Xytovl]

I don't think there is a fastboot option, when I grep the source I have

[shgadwa]

So, if I got this right...

Patching the kernel only helps in the seconds before init takes over, right? So its only going to speed up loading the kernel...right? Also, I found out that using the fastboot option does not cause gentoo to not check the hard drive... I don't know where I read that it did.

There is one thing I found that helps a lot... that is, to put xdm on the boot runlevel. This never worked for me in the past. It would lock up 80% of the time. And then I found out that xdm cannot run without hald and dbus. So, I moved them over to the boot runlevel... and now it works. Of course, it doesn't make the computer bootup faster but it load the login window earlier which means you can type in your password while its still booting up.

It would be really nice if we could speed up the loading from the login window to xfce. It seems to take 10-15 secs and it would be really nice if that could be shortened.

Another problem I have is that there are some things that I need to load at boot... such as /opt/lampp/lampp and such. The problem is that it takes about 5 seconds for lampp to startup. I could set it as a application that automatically starts after the computer boots up... but that did not work for me because I need to be root to do that. But, maybe I can just change folder ownerships?

Then there's a lot of other things that I recently am finding a need for... such as openSSH and samba, and such. I've added these to the default runlevel and now my computer boots up in 29-33 secs instead of 23. It would be nice if I could make it load faster.

[VinzC]

[shgadwa]