Re: parted / partition type

[Andrew Clausen]

Hi Scott :-)

Scott Scriven wrote:
> The information I'm trying to get from parted is the "0x83" or
> "Apple_HFS".  The type of filesystem isn't important to me.
> Currently, I'm using a combination of the fstype, minor number,
> and the partition flags to determine what the partition type
> is.
> 
> The goal is to allow the program to work using newbie language.
> There are only 7 partition configurations the user will see:
> 
>   Newbie Term           PType           Flags   Filesystem
>   -----------           -----           -----   ----------
>   Mac OS        <->     Apple_HFS               hfs
>   Linux         <->     Apple_UNIX_SVR2         anything
>   Linux root    <->     Apple_UNIX_SVR2 root    anything
>   Linux swap    <->     Apple_UNIX_SVR2 swap    swap
>   Bootloader    <->     Apple_bootstrap boot    hfs
>   Unused        <->     Apple_Free
>   Error         <->     Any other configuration is "incorrect"
> 
> I don't need to know the fstype, except when resizing
> partitions.  Formatting is completed later.

OK, I guess that looks good.

> > What do you mean by "formatted correctly"?
> 
> Your guess was correct.  An Apple_HFS with an ext2 filesystem
> would be "incorrect" or unformatted.  Also, if I removed a
> valid linux-swap partition and placed an Apple_bootstrap at the
> same starting point, that would be considered unformatted.

So, if a user "naïvely" does mkfs.ext2 on their macos partition,
(they don't want it any more!) and installs linux there,
are you going to reformat it to HFS for them?

I think the on-disk file system is much more important than
what the partition table says, so rather than treating the
the partition as unformatted, I would treat the partition
table as incorrect.

To do this in libparted, just do:

        ped_partition_set_system (part, part->fs_type);

libparted doesn't do this automatically, because there might
be deep-and-meaningful reasons why this is a bad idea on
some platforms.  Better to leave things as-is, IMHO.

In future, I think I will add: partition type looks insane.
Fix?

> I don't really need to know if a partition is "formatted
> correctly".  I'm just using it as a way to figure out what the
> partition type is, so I can figure out which of the 7
> newbie-level types it is.

Well, looking at the data is better than the partition ID, IMHO

> > What kind of libparted interface do you have in mind?
> 
> The current interface is nice.  The only thing I would change
> is to add one more column to its "print" output, to display the
> partition type.

***LIBPARTED***

Andrew Clausen