[ale] Questionable output from fdisk -l

[Scott Castaline]

Daniel Kahn Gillmor wrote:
> On Tue 2007-09-25 14:20:23 -0400, Scott Castaline wrote:
>
>   
>> Disk /dev/dm-7 doesn't contain a valid partition table
>>
>> This goes through to dm-15, with the only difference being the
>> capacity/geometry listed for each. I also noticed in /dev that there
>> are block device files for dm-7 to dm-15. What do these represent? 
>>     
>
> the dm-X devices come from devmapper, the ultra-flexible Linux block
> device abstraction layer.  LVM makes much use of devmapper.  each LV
> (logical volume) in an LVM system has its own block device.
> Naturally, there's no reason to put a partition table on an LV, which
> explains why fdisk can't find a legitimate partition on any of
> /dev/dm-7 through /dev/dm-15.
>
> You can figure out which /dev/dm-* is which by matching device node
> major and minor numbers.  For example, on my system, /dev/dm-3 is my
> swap LV:
>
> [0 dkg at squeak ~]$ ls -la /dev/dm-5
> brw-rw---- 1 root disk 253, 5 2007-09-14 14:48 /dev/dm-5
> [0 dkg at squeak ~]$ ls -la /dev/mapper | grep ' 253, *5 '
> brw-rw----  1 root disk 253,  5 2007-09-14 14:48 squeak0-swap
> [0 dkg at squeak ~]$ 
>
> These major and minor node numbers might switch around across various
> manipulations of LVM (including reboots) so don't count on them to be
> static.
>
> hth,
>
>         --dkg
>   
> ------------------------------------------------------------------------
>
> _______________________________________________
> Ale mailing list
> Ale at ale.org
> http://www.ale.org/mailman/listinfo/ale
I thought it did have to do with the LVM, but why isn't there dm1 - dm6? 
Also I had read somewhere that the GUI in Fedora has a problem with 
creating the VG/LV on a raw drive and since I was using the GUI I 
created a single linux partition on the 160GB SATA drive and 4 equal 
linux partitions on the 500GB drive. Would that be a problem you think?