[linux-lvm] Re: linux-lvm digest, Vol 1 #602 - 14 msgs

[Kirby C. Bohling]

bash> cat /proc/lvm/VGs/data/LVs/develop


name:         /dev/data/develop
size:         20971520
access:       3
status:       1
number:       3
open:         1
allocation:   2
device:       58:03

(My VG is data, my LV is develop), the last line has the device number on it.


The other place to look is:

bash> ls -la /dev/data/develop

brw-rw----    1 root     disk      58,   3 Apr 12 17:56 develop

58,3 is (major, minor).  The trick is figuring out which ones are decimal, and 
which ones are hex.  I believe the ls -la are decimal, but when you put it in 
for root= it has to be in hex.

In this case, I believe 58 is the major, and 3 is the minor.
(I could be completely wrong on that decimal/hex thing, I just remember that 
being an issue for me in the past when looking at root= on the command line once 
in the past).

Ahhh, looking a bit more:

bash> stat /dev/data/develop

   File: "/dev/data/develop"
   Size: 0               Blocks: 0          IO Block: 4096   Block Device
Device: 309h/777d       Inode: 16521       Links: 1     Device type: 3a,3
Access: (0660/brw-rw----)  Uid: (    0/    root)   Gid: (    6/    disk)
Access: Fri Apr 12 17:56:53 2002
Modify: Fri Apr 12 17:56:53 2002
Change: Fri Apr 12 17:56:53 2002

Which would confirm that root= must be in hex, 3a (hex) = 58 (decimal).  It has 
to be 4 digits long so in this case it would be "root=3a03".  The Device Type: 
is where the 3a03 comes from...

	Hope this helps.


		Kirby


James B. Byrne wrote:
> On Thu, 30 May 2002 19:45:33 +0200
> Thierry DE CARVALHO <thierry.decarvalho at online.fr> wrote:
> 
> 
>>Try with grub (here /dev/vg00/lvol1 is the root fs):
>>
>>title=GNU/Linux Debian 2.2 (potato)
>>kernel (hd0,1)/vmlinuz-2.2.19 root=3a00 ramdisk_size=8192 vga=10
>>#                                   ^^^^ <major><minor> of the lv
>>#                                   device
>>in hex
>>initrd (hd0,1)/initrd-lvm-2.2.19.gz
> 
> 
> I am afraid that this does not make a lot of sense to me.  Where 
> does one get the major/minor numbers for the logical volume?
> 
> Regards,
> Jim
> ---     e-mail is NOT a secure channel 
> James B. Byrne                mailto:ByrneJB at Harte-Lyne.ca
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