[bug#28145] [PATCH] build: Do not store two copies of the ISO-9660 superblock anymore.

[bug#28145] [PATCH] build: Do not store two copies of the ISO-9660 superblock anymore.

[Danny Milosavljevic]

* gnu/build/vm.scm (make-iso9660-image): Do not store two copies of the
ISO-9660 superblock anymore.
---
 gnu/build/vm.scm | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/gnu/build/vm.scm b/gnu/build/vm.scm
index 727494ad9..409320b1a 100644
--- a/gnu/build/vm.scm
+++ b/gnu/build/vm.scm
@@ -379,19 +379,6 @@ GRUB configuration and OS-DRV as the stuff in it."
                             "var=/tmp/root/var"
                             "run=/tmp/root/run"
                             "--"
-                            ;; Store two copies of the headers.
-                            ;; The resulting ISO-9660 image has a DOS MBR and
-                            ;; one protective partition (with type 0xCD).
-                            ;; Because GuixSD only uses actual partitions
-                            ;; rather than what /proc/partitions returns, work
-                            ;; around it by storing the primary volume
-                            ;; descriptor twice, once where it should be and
-                            ;; once in the partition.
-                            ;; Allegedly, otherwise, many other GNU tools
-                            ;; (automounters etc) would also be confused by
-                            ;; the extra partition so it makes sense to
-                            ;; store two copies in any case.
-                            "-boot_image" "any" "partition_offset=16"
                             "-volid" ,(string-upcase volume-id)
                             ,@(if volume-uuid
                                   `("-volume_date" "uuid"

[bug#28145] [PATCH] build: Do not store two copies of the ISO-9660 superblock anymore.

[Ludovic Courtès]

Hello Danny,

Danny Milosavljevic <dannym@scratchpost.org> skribis:

> * gnu/build/vm.scm (make-iso9660-image): Do not store two copies of the
> ISO-9660 superblock anymore.

Why is it no longer needed?  Otherwise fine with me.  :-)

Ludo’.

[bug#28145] [PATCH] build: Do not store two copies of the ISO-9660 superblock anymore.

[Danny Milosavljevic]

Hi Ludo,

On Tue, 22 Aug 2017 15:07:28 +0200
ludo@gnu.org (Ludovic Courtès) wrote:
> Danny Milosavljevic <dannym@scratchpost.org> skribis:
> 
> > * gnu/build/vm.scm (make-iso9660-image): Do not store two copies of the
> > ISO-9660 superblock anymore.  
> 
> Why is it no longer needed?  Otherwise fine with me.  :-)

Because we went ahead and now we just read it from the whole disk on boot (previously, it only accepted superblocks on partitions, remember?).

Previously on master:

- DVD
  + ISO9660 superblock
  + partition table
    + partition
      + ISO9660 superblock copy <--- GuixSD sees this

Now on master:

- DVD
  + ISO9660 superblock <--- GuixSD sees this
  + partition table
    + partition
      + ISO9660 superblock copy <--- what's this for now?

With the patch:

- DVD
  + ISO9660 superblock <--- GuixSD sees this
  + partition table
    + partition

[bug#28145] [PATCH] build: Do not store two copies of the ISO-9660 superblock anymore.

[Ludovic Courtès]

Danny Milosavljevic <dannym@scratchpost.org> skribis:

> Hi Ludo,
>
> On Tue, 22 Aug 2017 15:07:28 +0200
> ludo@gnu.org (Ludovic Courtès) wrote:
>> Danny Milosavljevic <dannym@scratchpost.org> skribis:
>> 
>> > * gnu/build/vm.scm (make-iso9660-image): Do not store two copies of the
>> > ISO-9660 superblock anymore.  
>> 
>> Why is it no longer needed?  Otherwise fine with me.  :-)
>
> Because we went ahead and now we just read it from the whole disk on boot (previously, it only accepted superblocks on partitions, remember?).
>
> Previously on master:
>
> - DVD
>   + ISO9660 superblock
>   + partition table
>     + partition
>       + ISO9660 superblock copy <--- GuixSD sees this
>
> Now on master:
>
> - DVD
>   + ISO9660 superblock <--- GuixSD sees this
>   + partition table
>     + partition
>       + ISO9660 superblock copy <--- what's this for now?
>
> With the patch:
>
> - DVD
>   + ISO9660 superblock <--- GuixSD sees this
>   + partition table
>     + partition

Thanks for the explanation, got it now.

Ludo’.

[bug#28145] [PATCH] build: Do not store two copies of the ISO-9660 superblock anymore.

[Ludovic Courtès]

Hi Danny,

Just a reminder that this patch hasn’t been applied.  TIA!  :-)

Ludo’.

ludo@gnu.org (Ludovic Courtès) skribis:

> Hello Danny,
>
> Danny Milosavljevic <dannym@scratchpost.org> skribis:
>
>> * gnu/build/vm.scm (make-iso9660-image): Do not store two copies of the
>> ISO-9660 superblock anymore.
>
> Why is it no longer needed?  Otherwise fine with me.  :-)
>
> Ludo’.