[parted-devel] File System Type Not Detected with 4096 byte Sector Size Device

[Curtis Gedak]

Jim Meyering wrote:
> Curtis Gedak wrote:
>> My testing using blkid to detect file systems on devices with a 4096
>> byte sector size has proven quite promising.  One difference of note
>> is that blkid does not display an entry for extended partitions.
>>     
>
> Do you mean that libblkid does not display a file system type for
> an msdos extended partition?  That makes sense, since the
> extended partition is just a container for other partitions,
> and hence has no file system of its own.

I have not worked with the libblkid library directly myself.  It might 
or might not recognize an msdos partition table extended partition.

My observation is that the blkid command will not return any textual 
information if run on an extended partition.

For example if /dev/sda4 is an extended partition, the following command 
will not return any text:

     $ blkid -c /dev/null /dev/sda4
     $ echo $?
     2
     $

The return code value is 2 in this case.

For primary and logical partitions containing a file system, the return 
code appears to be 0.