Re: wait for the boot device

[Ferenc Wagner <wferi@niif.hu>]

md@Linux.IT (Marco d'Itri) writes:

> On Mar 22, Ferenc Wagner <wferi@niif.hu> wrote:
>
>> devices, btw.  How do you feel about including something like this?
>
> I am not aware of this issue. Do you have a patch?

This is what I usually employ:

$ cat /etc/initramfs-tools/scripts/init-premount/scsi_wait_scan 
#!/bin/sh

PREREQ="udev"

prereqs()
{
        echo "$PREREQ"
}

case $1 in
# get pre-requisites
prereqs)
        prereqs
        exit 0
        ;;
esac

. /scripts/functions

log_begin_msg "Waiting for SCSI scan to finish"
modprobe scsi_wait_scan
modprobe -r scsi_wait_scan
_log_msg "udev to process events ... "
wait_for_udev
log_end_msg

The same could be achieved by inserting the above modprobes before
udevadm settle in /usr/share/initramfs-tools/scripts/init-premount/udev,
and it's the very point of those lines, I guess: to wait for the
necessary devices to appear.  Of course not all systems have a SCSI
bus, so some extra cleverness would also be required.  But this is a
very frequent reason for boot failure after installation, and
something really should be done about it.  Rootdelay is of course
documented, but that isn't a technically sound practice.  Let's find
one, if possible!
-- 
Cheers,
Feri.