Speed up boot!

[zieloo]

On a 466MHz old celeron with 128 megs of ram it takes up to 20 secs. for a login screen to show up + a few more to start X + a light windowmanager. So i don't understand you guys... You've got ~ 2 Mhz & ~512 Mb machines a cry because you have to wait 1-2 minutes to load kde? Maybe you should use an old computer, instead.

Speeding up your computer is all about choices... You must decide what services (and how many) to start and resign

Also very inportant is kernel version and applied configuration. Now i'm using 2.6.7-ck5 sources with loadable modules support turned off. This enlarged my kernel up to about 1.2Mb (could be smaller...), but since i don't need to load any extra modules i feel more comfortable...

So - to sum up - starting Linux in less than 30 secs. is not a problem... Comparing to Windows - you save time even if it takes 2 mins. to boot...

[fourwood]

Sure a one minute bootup time isn't horrible. But, if it can be shorter, why not make it that way? I don't see the point in telling people to be happy with what they have if they can make it better.

[F.Ultra]

It might be ridicolous to whine about slow boot, but for many people this is a big problem, some of us tends to do many reboots (I for one dual boots with XP so there can be quite some switching on busy days on my development machine). Also never underestimate the nice feeling that you Linux box boots faster than that windows machine!

I see the problem as Linux beeing very targeted for server use and hence loads everthing in order to be 100% sure that everything works ok. Compare this with a desktop system as XP and they have no need to start all services beforehand (as compared with w2k3 that is XP for servers and that has quite a bit longer boot-time).

What I would like to see is a way to get local up really fast and after that begin to start other services. For example I have a very slow DHCP server (a cisco router that has gone mad for some strange reason) that most of the time waits nearly 2 minutes before handing out addresses so I have to wait roughly 2 minutes every boot for net.eth0 to start so ntp-client and ntpd also can start. As in XP these should really have been started after I got a login prompt (or at the exact same time). Putting net.eth0 into background won't help either since that would make ntp-client and ntpd to fail.

So is there a way to hack the Linux boot process to bring up local right after kernel so that we could have almost subsecond booting, and then start all services in silent background while the user enters username and password ? I bet there is, but it might be quite hard to do (?)

[Kaali]

Well, some of us are geeks, hackers even. It is fun to play with your toys. I don't boot that often, but i had a boring night so it thought that if i would take booting faster as a problem for me to solve i wouldn't be that bored. Well, i managed to shave a minute of my bootup time so the end result is pleasing and it was fun to do. Why would you ever want to walk with your hands, your legs are better at it, because it's fun! Why would you want to run a system on an emulator that you already own, because it's interesting and that is what us geeks do

[asph]

thank you for the post Kaali, great tweaks to speed up boot process

also this thread is very educational to learn and understand boot process
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[NightSpirit]

[floam]

[NightSpirit]

Sorry floam, clearly don't check my email anough either

The init script I use for gdm (as apposed to using existing xdm script) is as follows:

[nsahoo]

Although faster boot time can be really useful, I'd hate to compare with XP, because, showing the desktop while it's not ready seems like a lie to me.

[Nightscape]

Do you think this could be done in Gentoo?
http://www-106.ibm.com/developerworks/linux/library/l-boot.html?ca=dgr-lnxw04BootFaster
It's a HowTo for making the boot process be driven by make and use it's abilities to handle dependencies and multi-threading.

[Phlogiston]

[Phlogiston]

I managed that xdm is started before other services, but it seems like it waits until the last service is started... I don't know why? Could anybody help me?

[Titeuf]

If you use dhcp for your network, the following greatly increased the speed of it:
Edit /etc/init.d/net.eth0
and command the whole if-block under "Stop DHCP..."
Example:

[seppe]

I load everything from the default runlevel in the background.

First I removed xdm from the default level, and moved it too boot level

[syadnom]

here is another idea..

how about finding a way to compress all files used for booting the machine.

lets make a highly compressed initrd, so your hd does not need to read as much data(compressed ) and your CPU can do the work

in most circumstances, the CPU is not loaded fery much during boot, the HD is what the slow point is. so if you can get data from the drive faster, the CPU will compensate for the compression and boot times should be improved.

im not sure what compression methods can be used with initrd, but assuming bz2 were ok.

dd if=/dev/null of=/boot/initrd-compressed bs=1k count=4
for a 4k initrd

make an ext2 filesystem using loopback
losetup /dev/loopx /boot/initrd-compressed
mkfs.ext2 /dev/loopx
mount /dev/loopx /mnt/initrdbuild

build your initrd with every file accessed during boot that will fit into initrd, including modules if used/needed.

unmount image and bz2 it up, set that as initrd and try it out.

the more the compression, the faster the initrd will load from disk, the less time the HD will need to be accessed.

this should shave a few seconds off

any thoughts??

[syadnom]

bs=1k should have been bs=1M


also, you can make your initrd larger via a kernel config, any size you wish. i would recommend moving up to 8096 for some room to maneuver.

here is a link to an initrd guide
https://forums.gentoo.org/viewtopic.php?t=193273&highlight=build+initrd

also, gzip is normally used to compress initrds. this may not be optimal and im not sure if this can be changed. you COULD use the --nocompress option on mkinitrd and then compress the initrd file with bz2 afterwards just to check it out. will work on this tomarrow.

[syadnom]

just read through the gentoo init guide.

i think the the dependancy resolution causes some slowdown. for scripts that you know need to be run in a certain order, you COULD

rc-update remove foo default
where foo is any and all packages that you know have no dependacies.

then,

cat foo1 foo2 foo3 foo4 foo5 > foo1_2_3_4_5_group
then
rc-update add foo1_2_3_4_5_group default.

go in and edit foo1_2_3_4_5_group, and remove ALL dependancies.(all need= or use=) and add those to the very first entry, so all dependancies are resolved in the first part and the dependacy checks are not repeated.

i would suggest building like scripts. as in put smbd, nfsd, ftpd, sshd in a script with the only dependancy being need="net"

this may help shave seconds off by skiping a lot of the dep checking,

[syadnom]

just a thought, above idea is untested!!!

[syadnom]

one could use "softlevels" to test these ideas without risking a nuked system. just create a second 'default' run level called 'testing' and put all your runscripts into theim, full edited and ready to blow, then add a new grub/lilo line of softlevel=testing

this will skip 'default' and use 'testing' instead.

[alligator421]

[sapphirecat]

[syadnom]

all of the login managers use the settings of XDM for when to init. no matter what you do the DM will start AFTER init in most circumstances.

instead of hacking up init, we need SLIGHT modifications

such ass.

move all non-critical services to another runlevel.

move net, netmount, hotplug, etc into a 'postinit' runlevel

in default, add a init script that does a 'init postinit &'

this way, XDM/GDM/KDM will start up just after all of the really important stuff like localmount, but still not destroy the dependancy system gentoo has. this new runlevel will only be run when the system is passed the command 'init postinit &, and it will background it, allowing XDM to start up right after 'default'

then rc-update still works. you just 'rc-update add foo postinit'

i'll try now

--

by the way, make a custom init script that ONLY ran gdm, placed it in the default runlevel with a 'depend() { before *}' and it still waits until init is done. again, this is the DMs looking at XDM config script.

[syadnom]

so i dont know how to start up another runlevel without dropping the old one.

so here is the plan.

the postinit runlevel needs to have EVERY init script that default does or else when you switch to it all inits that are not in postinit will die.

also, you have to edit /etc/inittab and change the runlevel 4(3,4,5 are all set to default) to postinit.

then make a small init script(i will post one) that initializes the next runlevel by running init 4.

this way, the little remaining in default will start first, and then postinit will start afterwards, but since the default runlevel is complete, XDM should start. ill try now

by the way, im actually not using default as the runlevel to mess up, but have a 'x' runlevel and am using softlevel=x as a kernel param at boot.

[syadnom]

ok, so here it is

#you must, create a new runlevel in /etc/runlevels

su

mkdir /etc/runlevels/fastboot

#now, copy ALL inits from boot and default into fastboot

cp /etc/runlevels/boot/* /etc/runlevels/fastboot
cp /etc/runlevels/default/* /etc/runlevels/fastboot

#now make a nice safe copy of boot and default

cp -r /etc/runlevels/boot /etc/runlevels/boot.safe
cp -r /etc/runlevels/default /etc/runlevels/default.safe

#now, delete everything from boot runlevel, except localmount and checkfs and checkroot

cd /etc/runlevels/boot
rm foo1 foo2 foo3 foo4

#now edit the localmount, make the ONLY deps

depend() {
need checkroot checkfs
}

# change deps of checkfs to "checkroot"
# change deps of checkrootto "before *"

now edit /etc/inittab and change runlevel 4 to fastboot, you will notice 3 lines that end with default.

now you need to add the line

init 4 &

into your Xsession file at the very end.

---

ok, now your machine will startup with NOTHING, then xdm will start and in the background the rest of init will come up

hopefully

this works on my machine, though it may NOT work on yours
remember, you backed up your original boot and defaults so you can restore your system

all you need to do is copy boot and default back to their original places, then delete the added line to Xsessions and reboot

USE AT YOUR OWN RISK

--

my actual boot time DID NOT IMPROVE, BUT i am at a login prompt in nearly half the time. this make the whole system feel like it booted faster.

--

also, this may not work if you have to load video modules as the modules init is not run until after X is started, BUT you can remove the deps on modules and put it back into the boot runlevel if needed.

--

also, you will now need to use fastboot as your only runlevel when adding things via rc-update

rc-update add foo fastboot

unless you need it in boot, then you can use boot, BUT if it has any deps, they will be loaded, and if the deps have deps, they get loaded and so on, pretty soon everything is starting before XDM again.

[fallingcow]

Anyone else have problems with the kernel loading uber slow?

I'm talking about the part right after the bootloader where it's like:

loading linux.................................

I've looked all over and not been able to find anyone else with this problem, and it only happens on my laptop. My other machines all load the kernel in less than 2 seconds, no matter how much crap I compile into it, but my laptop can take 10 seconds or more for a medium-large kernel, with little pauses between each ".". What gives? Even if I move as much functionality to modules as I can, it still takes longer than some of my other boxen with kernels twice as large. I've installed Linux (not necessarily Gentoo, all the time) on some very low-end desktop machines and never seen this happen, and my laptop is only a year old, so I don't think it's a slowdown due to the hardware.

Help? If this has been discussed before, please direct me to the thread, as I've been unable to find it.
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