Re: kernel/initrd loading delays

Dave Young
2015-10-14T09:04:47Z

On 10/12/15 at 12:29pm, Felix Miata wrote:
> On more and more installations since most distros have replaced mkinitrd with
> dracut, on selecting a bootloader menu choice the "root
> (hd0,...filesystemtype..[Linux-bzImage, setup, ... initrd /boot/initrd"
> message stays on screen 40 seconds or more before the time-stamped boot
> messages begin scrolling the screen. IIRC, these delays first began appearing
> last January or February, and appear on multiple machines. All kernel and
> initrd images are on smallish EXT3 or EXT4 (mostly the latter) filesystems
> using 1024 blocksize on BIOS logical partitions on rotating rust (IIRC, all
> with native 512b sector size, manufactured in 2011 or earlier). All
> installations are configured with static IP. All have Plymouth either not
> installed, or are booted with noplymouth included on kernel cmdline.
>
> e.g, on my fastest system, host msi85, a 3.0 GHz dual core Haswell, total
> time from boot stanza select on BIOS host msi85 to Rawhide 4.3.0-0.rc3.git4.1
> (dracut initramfs.img 11,326,223) multi-user.target shell prompt ready is
> about 80 seconds following that 40 second delay, with last time stamp showing
> 36.844484.
>
> Same msi85 system booting LMDE 2 3.16.0-4 (non-dracut? initrd.img 27,362,964;
> initramfs-tools 0.120) delays start of boot messages nearly 80 seconds,
> reaching DM greeter ready nearly 140 seconds after stanza selection.
>
> Same system booting openSUSE Leap 42.1 4.1.8 (dracut initrd 8,082,360)
> exhibits no perceptible delay, reaching multi-user.target shell prompt in
> under 47 seconds from boot stanza selection.
>
> Same system booting openSUSE 13.2 3.16.7 (dracut initrd 5,351,996) delays
> start of boot messages about 40 seconds, reaching multi-user.target bash
> prompt about 90 seconds after stanza selection.
>
> Same system booting Mageia 5 4.1.8 (dracut initrd.img 9,391,664) exhibits no
> delay, reaching multi-user.target bash prompt in about 45 seconds.
>
> Same system booting Wheezy 3.2.0 (non-dracut initrd.img 10,537,321) exhibits
> no delay, reaching DM greeter in less than about 45 seconds.
>
> Same system booting openSUSE 13.1 3.12.44 (non-dracut initrd 7,679,390)
> exhibits no delay, reaching multi-user.target bash prompt in less than 45
> seconds.
>
> Same system booting Fedora 23 4.2.2 (dracut initramfs.img 11,255,214) reaches
> multi-user.target shell prompt in about 75 seconds after unknown
> kernel/initrd delay (puts display into sleep mode until boot messages appear).
>
> Same system booting openSUSE Tumbleweed 4.2.1 (dracut initrd 8,970,760)
> exhibits no delay, reaching multi-user.target bash prompt in less than 45
> seconds.
>
> Same system booting (second, on sda28, vs. other on sda23) openSUSE
> Tumbleweed 4.2.1 (dracut initrd 8,965,124) exhibits ~40 second delay,
> reaching multi-user.target bash prompt in about 100 seconds.
>
> Same system booting Kubuntu 14.10 3.16.0 (non-dracut initrd 20,550,608)
> exhibits no initial (linux/initrd) delay, reaching KDM greeter in about 90
> seconds.
>
> Same system booting Fedora 22 4.1.8 (dracut initrd 10,788,392) exhibits no
> delay, reaching multi-user.target bash prompt in less than 50 seconds.

Wow, you are using so many distributions.

From your previous tests, I feel it should not be a dracut problem.
But you need first find where is the delay from, bootloader, kernel, or somewhere else.
I think you can select one distribution delaying happend, try older kernel
if the older kernel does not have the delay then it should be kernel problem.

As for boot loader, they may have some debug options but I do not know that
much.

Thanks
Dave