Libguestfs - May 2015 - Re: [PATCH v2 04/11] resize: add support for logical partitions for calculate_surplus

On Wed, May 20, 2015 at 06:51:30AM -0400, Chen Hanxiao
wrote:
> Add support for logical partitions.
>  - count number of logical_partition (we've split partitions list)
>  - don't count size of extended partition
>    For it'll duplicate with logical partition, we'll count it later
>  - we need at leat 1 gap between logical partitions.
>    so --aligment=1 will be increased by 1
> 
> Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
> ---
>  resize/resize.ml | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/resize/resize.ml b/resize/resize.ml
> index 92f7304..a0ed713 100644
> --- a/resize/resize.ml
> +++ b/resize/resize.ml
> @@ -741,8 +741,10 @@ read the man page virt-resize(1).
>      (* We need some overhead for partitioning. *)
>      let overhead >        let maxl64 = List.fold_left max 0L in
> +      (* We need at least 1 sector gap between logical partitions *)
> +      let alignment = if alignment = 1L then 2L else alignment in
>  
> -      let nr_partitions = List.length partitions in
> +      let nr_partitions = List.length partitions + List.length
logical_partitions in
I don't understand this at all.  Why do logical partitions count
towards the surplus?  I don't think they do.

Rich.
>        let gpt_start_sects = 64L in
>        let gpt_end_sects = gpt_start_sects in
> @@ -770,12 +772,23 @@ read the man page virt-resize(1).
>      let required = List.fold_left (
>        fun total p ->
>          let newsize > +          (* size of extended partition is
calculated seperately *)
> +          if p.p_type = ContentExtendedPartition then 0L else
> +            match p.p_operation with
> +            | OpCopy | OpIgnore -> p.p_part.G.part_size
> +            | OpDelete -> 0L
> +            | OpResize newsize -> newsize in
> +        total +^ newsize
> +    ) 0L partitions in
> +    let required = required +^ List.fold_left (
> +      fun total p ->
> +        let newsize >            match p.p_operation with
>            | OpCopy | OpIgnore -> p.p_part.G.part_size
>            | OpDelete -> 0L
>            | OpResize newsize -> newsize in
>          total +^ newsize
> -    ) 0L partitions in
> +    ) 0L logical_partitions in
>  
>      let surplus = outsize -^ (required +^ overhead) in
>  
> -- 
> 2.1.0
> 
> _______________________________________________
> Libguestfs mailing list
> Libguestfs@redhat.com
> https://www.redhat.com/mailman/listinfo/libguestfs
-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
Fedora Windows cross-compiler. Compile Windows programs, test, and
build Windows installers. Over 100 libraries supported.
http://fedoraproject.org/wiki/MinGW

On Thu, May 28, 2015 at 12:11:17PM +0100, Richard W.M. Jones
wrote:
> On Wed, May 20, 2015 at 06:51:30AM -0400, Chen Hanxiao wrote:
> > Add support for logical partitions.
> >  - count number of logical_partition (we've split partitions list)
> >  - don't count size of extended partition
> >    For it'll duplicate with logical partition, we'll count it
later
> >  - we need at leat 1 gap between logical partitions.
> >    so --aligment=1 will be increased by 1
> > 
> > Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
> > ---
> >  resize/resize.ml | 17 +++++++++++++++--
> >  1 file changed, 15 insertions(+), 2 deletions(-)
> > 
> > diff --git a/resize/resize.ml b/resize/resize.ml
> > index 92f7304..a0ed713 100644
> > --- a/resize/resize.ml
> > +++ b/resize/resize.ml
> > @@ -741,8 +741,10 @@ read the man page virt-resize(1).
> >      (* We need some overhead for partitioning. *)
> >      let overhead > >        let maxl64 = List.fold_left max 0L
in
> > +      (* We need at least 1 sector gap between logical partitions *)
> > +      let alignment = if alignment = 1L then 2L else alignment in
> >  
> > -      let nr_partitions = List.length partitions in
> > +      let nr_partitions = List.length partitions + List.length
logical_partitions in
> 
> I don't understand this at all.  Why do logical partitions count
> towards the surplus?  I don't think they do.
OK I guess the answer is because logical partitions now need their
own alignment (within the extended partition), and that contributes
to the required surplus for the disk.

Do we resize the extended partition sufficiently (eg. if the extended
partition has 100 aligned logical partitions)?

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html

> -----Original Message-----
> From: Richard W.M. Jones [mailto:rjones@redhat.com]
> Sent: Thursday, May 28, 2015 7:16 PM
> To: Chen, Hanxiao/陈 晗霄
> Cc: libguestfs@redhat.com
> Subject: Re: [Libguestfs] [PATCH v2 04/11] resize: add support for logical
partitions
> for calculate_surplus
> 
> On Thu, May 28, 2015 at 12:11:17PM +0100, Richard W.M. Jones wrote:
> > On Wed, May 20, 2015 at 06:51:30AM -0400, Chen Hanxiao wrote:
> > > Add support for logical partitions.
> > >  - count number of logical_partition (we've split partitions
list)
> > >  - don't count size of extended partition
> > >    For it'll duplicate with logical partition, we'll
count it later
> > >  - we need at leat 1 gap between logical partitions.
> > >    so --aligment=1 will be increased by 1
> > >
> > > Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
> > > ---
> > >  resize/resize.ml | 17 +++++++++++++++--
> > >  1 file changed, 15 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/resize/resize.ml b/resize/resize.ml
> > > index 92f7304..a0ed713 100644
> > > --- a/resize/resize.ml
> > > +++ b/resize/resize.ml
> > > @@ -741,8 +741,10 @@ read the man page virt-resize(1).
> > >      (* We need some overhead for partitioning. *)
> > >      let overhead > > >        let maxl64 =
List.fold_left max 0L in
> > > +      (* We need at least 1 sector gap between logical
partitions *)
> > > +      let alignment = if alignment = 1L then 2L else alignment
in
> > >
> > > -      let nr_partitions = List.length partitions in
> > > +      let nr_partitions = List.length partitions + List.length
> logical_partitions in
> >
> > I don't understand this at all.  Why do logical partitions count
> > towards the surplus?  I don't think they do.
> 
> OK I guess the answer is because logical partitions now need their
> own alignment (within the extended partition), and that contributes
> to the required surplus for the disk.
> 
> Do we resize the extended partition sufficiently (eg. if the extended
> partition has 100 aligned logical partitions)?
> 
My fault, we don't need the surplus of logical partitions.

For resizing extended partition, is in:
[10/11] resize: add support resize extended partition
https://www.redhat.com/archives/libguestfs/2015-May/msg00103.html

For dealing with alignment of logical partitions, is in:
[06/11] resize: add support for logical partitions of
calculate_target_partitions
https://www.redhat.com/archives/libguestfs/2015-May/msg00098.html

Regards,
- Chen