[Libguestfs] [PATCH 00/10] virt-resize: add support for resizing MBR logical partitions

[Richard W.M. Jones]

On Wed, Apr 29, 2015 at 09:19:24AM +0000, Chen, Hanxiao wrote:
> commit 6e989fd709fea37430398cbb7c01c52cd44bd1ac already did this:
> we had p_mbr_p_type : partition_type in type partition.
> Like what MBR/EBR did, this patchset use `partition_type`:
> 
> /dev/sda3:
> 	partition data: 3 210763776-420478975 (209715200 bytes)
> 	bootable: false
> 	partition ID: 0x5
> 	content: extended partition
> 	label: (none)
> 	GUID: (none)
> 	*partition type: extended*
> /dev/sda5:
> 	partition data: 5 211812352-222298111 (10485760 bytes)
> 	bootable: false
> 	partition ID: 0x83
> 	content: unknown data
> 	label: (none)
> 	GUID: (none)
> 	*partition type: logical*
> 
> As we could only had one extended partition,
> all logical partitions belong to that extended partition,
> so current type partition of virt-resize can reflect logical/extended partition model. 

The specific problem is that the extended partition (eg /dev/sda3)
contains the logical partition (/dev/sda5).  Having a flat list
doesn't express that at all.

I agree it is very hard to express this, because extended partitions
just work so differently from how any sensible partition scheme should
work (because they are a big hack).  But perhaps:

 - flat list of primary partitions (as now, the global 'partitions')

 - one MBR extended partition (as a new global variable)

 - flat list of logical partitions

would do it?  It still has the problem that the extended partition is
a bit like a primary partition, yet isn't in the partitions list.

> > It's very hard to understand what changes are being made.  The commits
> > are not grouped in a way that makes them easily understandable to me.
> 
> I'll try to regroup them and make the patchset easy to review.

Thanks,

Rich.

-- 
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