Re: mount other than rootfs problem

[Cong Wang <amwang-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

于 2011年09月30日 10:17, Dave Young 写道:
> On 09/29/2011 11:18 PM, Cong Wang wrote:
>
>> 于 2011年09月29日 10:55, Dave Young 写道:
>>> Hi,
>>>
>>> In current dracut modules there's still fstab-sys for mount something
>>> other than root, So how about add a similar module ie. fstab-kdump which
>>> contains the kdump target device/fstype, add mount-kdump.sh to mount all
>>> the stuff. For rootfs we can use dracut mount point.
>>
>> I doubt fstab-sys module could mount all kinds of block devices, e.g.
>> LVM or RAID, because I see no code to detect/handle LVM/RAID in fstab-sys
>> or fs-lib module.
>
>
> I just tried a simple lvm mount, it was skipped due to there's no dev
> nodes. making the fstab-sys module depends on lvm also does not work,
> but mannually call lvm_scan in rdshell, then mannually mounting the lvm
> volume can success
>

Yeah, this is not strange, I bet you can also pass "rd_LVM_LV=" to
mount the target device.

> So If we properly deal with the dependency issue it should be possible
> to resolve. There's dracut module dependency currently, but question is
> that is there dependency of hooks? such as make the mount-sys hook
> depends on the lvm setup code, is it possible with current interface?
>

I don't think so, you called 'lvm_scan' and did mount manually, lvm
module itself will not mount it unless you add "rd_LVM_LV=". So, this
a not only a problem of module dependency, but also a problem
of lvm module code. For kdump, even using "rd_LVM_LV=" is not a good
choice, because we still need to convert the device name (or UUID) into
the correct kernel cmdline.

If some hook need some other module, then the whole module itself should
depend on that module, which can be expressed in depend().