udev and rebuilding kernal

windoze · 2008-01-09 04:09:44

hi, i just installed arch for the fouth time. I am trying out different ways to run the kernal. I have ide, but no raid or sata, so I removed the ones that i do not need, but now when i boot it does not mount the drive and i cant get to root. i need to rebuild the kernal but i dont know how.

also there is a big lag starting udev uevents. i tried puting pci=conf1 and then pci=nobios at the kernal line but they do not stop the lag. i cant find a solve at this board.

mcmillan · 2008-01-09 04:17:56

I'm not sure if this is the problem, but a few kernel updates back all the hard drives switched from /dev/hd* to /dev/sd* which seems like it's getting treated as a sata drive, even if it's ide. If you're compiling your own kernel this may not be the case though.

How long of a lag for udev are you getting. I use the default kernel and udev events seem to be one of the longer pauses I get during bootup, but it's only maybe 3 or 4 seconds.

windoze · 2008-01-09 04:22:36

i am using the default kernel. i modified the mkinitcpio.conf to now read "base udev ide" at install by harddrive, but it does not boot to root.

i have a p266 and the lag is about 30 sec. i tryed to download pkgbuild with packman but it did not work.

jacko · 2008-01-09 04:47:18

I have a high end dual core system and I get a good 2-3 second pause when udev loads. I would say your 266 is right on par, but then again I never tried running arch on a 266 p2.

windoze · 2008-01-09 04:52:35

i am not sure because there are many threads that talk about this udev lag. here one that says its a bug http://bbs.archlinux.org/viewtopic.php?id=40797

jacko · 2008-01-09 05:55:29

windoze wrote:

i am not sure because there are many threads that talk about this udev lag. here one that says its a bug http://bbs.archlinux.org/viewtopic.php?id=40797

Its like I said, I never tried it on a 266 p2 so I can't say, But I can verify a pause when udev loads.

Now if I overclock my dual core then udev does speed up, so I am not so sure its a bug.

byte · 2008-01-09 21:10:52

My Celeron 366 needs at least 20 seconds for loading uevents, so that sounds reasonable. Minimizing the initcpio image is a good idea, but it won't help much with udev.

phrakture · 2008-01-10 00:00:43

You know, if you don't know what you're doing with this, you should probably either NOT be messing with it, or at least know how to debug things.

For starters, your mkinitcpio image has "base udev ide". This is fine, but if you're trying to minimize modules, you did just the opposite:

$ mkinitcpio -H autodetect
Help for hook 'autodetect':
  This hook shrinks your initramdisk to a smaller size
  by autodetecting your needed modules. Be sure to verify
  included modules are correct and none are missing.
  This hook must be run before other subsystem hooks in
  order to take advantage of auto-detection.  Any hooks
  placed before 'autodetect' will be installed in full.

In addition, you removed the filesystems hook, so there are no filesystems there, and thus they can't be mounted

$ mkinitcpio -H filesystems
Help for hook 'filesystems':
  This hook is responsible for loading filesystems for the root device.
  Detection will be done at runtime.  If you would like to minimize the
  modules installed in the image, add the autodetect hook too.

Further more, if you REALLY want to minimize the set of modules and the hooks in mkinitcpio, the config file /etc/mkinicpio.conf actually explains what to do:

# MODULES
# The following modules are loaded before any boot hooks are
# run.  Advanced users may wish to specify all system modules
# in this array.  For instance:
#     MODULES="piix ide_disk reiserfs"
MODULES=""

# Examples:
#    This setup specifies all modules in the MODULES setting above.
#    No raid, lvm2, or encrypted root is needed.
#    HOOKS="base"

Now, after all this is said and done, I'm still going to recommend you do not edit this image and use the default. This is boot you're messing with and if you don't know what's going on under the hood, you have the potential to make your machine unbootable.

windoze · 2008-01-10 04:27:40

yes, not bootable as i already found that out. i dont mind playing with my os, as i am learning, slow but still learning a few things here and there. i have reinstalled before, it is fast by harddrive. nevertheless, how to speed up udev. there are many messages, bugs posted and as of yet, there is nothing that seems to work. take this post for example which is simular to what is happening here. http://bbs.archlinux.org/viewtopic.php?id=24315

Can i have some feeback on this, advanced on not. ty

Last edited by windoze (2008-01-10 04:33:00)

Arch Linux

#1 2008-01-09 04:09:44

udev and rebuilding kernal

#2 2008-01-09 04:17:56

Re: udev and rebuilding kernal

#3 2008-01-09 04:22:36

Re: udev and rebuilding kernal

#4 2008-01-09 04:47:18

Re: udev and rebuilding kernal

#5 2008-01-09 04:52:35

Re: udev and rebuilding kernal

#6 2008-01-09 05:55:29

Re: udev and rebuilding kernal

#7 2008-01-09 21:10:52

Re: udev and rebuilding kernal

#8 2008-01-10 00:00:43

Re: udev and rebuilding kernal

#9 2008-01-10 04:27:40

Re: udev and rebuilding kernal

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