[mythtv-users] 2.6.3-7 sds kernel and LVM2 for mythtv

[Michael T. Dean]

Mark Maas wrote:

> Michael T. Dean wrote:
>
>> Do you have dm-mod installed (i.e. modprobe dm-mod assuming you've 
>> build LVM support as a module)?
>
> Well well, modprobe lvm-mod did not work, but modprobe dm-mod does go 
> off without a hitch. So now the device mapper is installed and the 
> /dev/mapper/control is also there where it should be.
> Now: How do I create this module for it is not there yet. Strange... 
> for a 2.6.3 kernel...

/blind leads blind

I just started with LVM, but it seems to me that lvm-mod is used if 
you're using LVM1; whereas dm-mod is used with LVM2.  I actually have 
the lvm-mod module (because I built my kernel myself and built the 
module), but when I activate it, it's never used and all its "/proc" 
data is empty (i.e. no PV's, VG's, etc.) even though the device mapper's 
/dev/mapper directory contains all the appropriate info on my VG's and 
LV's.  Therefore, I'm assuming lvm-mod is an LVM1 only thing.

Unfortuanately, Red Hat has done an excellent job of getting LVM going 
and keeping development moving, but it seems that the pace of 
development has caused a lack of good documentation.  The HOWTO leaves a 
lot to be desired (i.e., "None yet," and, " FIXME: This needs to be 
filled in still," didn't advance my knowledge significantly) and there's 
not much other info out there--especially discussing the 
differences/changes between LVM1 and LVM2.  Note that I'm not 
complaining:  after all, I could always write some stuff up, but I'm 
waiting until I know a bit more about how it works before considering that.

In short, it seems to be working for me without lvm-mod, so I suggest 
(in a please-don't-blame-me-if-you-have-problems kind of way), you just 
use it and don't worry about lvm-mod.  Of course, if I am wrong, someone 
is likely to tell us...  ;)

Mike