Re: mount other than rootfs problem

[Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On 09/30/2011 11:27 AM, Cong Wang wrote:

> 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.


Add lvm_scan in mount-sys.sh also works, so if we can make lvm_scan
being called automaticlly via dependencies it will be good. OTOH fstab
is better than cmdlines as an interface for multi-target dumping

> 
>> 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.


Yes, agree

>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.


not understand yet, could you help to explain or give an example?

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



-- 
Thanks
Dave