Re: [RESEND PATCH 1/2] init: Add support for root devices to bespecified by partition name

[Kirill Smelkov]

On Fri, Jan 07, 2011 at 04:13:27PM +0100, Kay Sievers wrote:
> On Fri, Jan 7, 2011 at 12:42, Kirill Smelkov <kirr@xxxxxxxxxxxxxxxxxxx> wrote:
> >  [ In follow-up to b5af921e ]
> >
> > Besides GUIDs, there are also partition names stored in an EFI GPT
> > partition table. So let's add support for root to be located not only by
> > GUID, but also by partition names, like this:
> >
> >    root=PARTNAME=<partition-name>
> 
> Are you sure about this? What's your use case?
>
> Generally, we really don't recommend ever to use any simple labels for
> critical stuff -- not from filesystems, not from partitions.
> 
> I know that some distros did that, but this is pretty misguided, and I
> think, should not be extended to any new facility, unless there is a
> good use case for that.
> 
> Labels are not unique and in the general case absolutely not useful to
> uniquely identify data on a disk. They only make sense for humans, or
> interfaces that visualize things -- they should usually not be used in
> any environment that reliably needs to identify a certain partition.
> We have the uuids  for a reason.

I'm regularly rebuilding flash image for one product and at present in
bootloader we have 

    kernel      /boot/vmlinuz root=LABEL=NAVY-root ...


which requires loading initrd which I've tried to avoid with
root=PARTNAME=... We needed this stuff in the first place so that
device could be booted over compact-flash or usb or whatever.

Yes, this could be changed to using root filesystem uuid (although
labels as you say are easier for humans to understand), and I see your
point about reliability. So sorry for the noise coming from "misguided"
heritage.

Thanks,
Kirill

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