[linux-lvm] 2.4 LVM1 devfs -> 2.6.0 LVM2 udev

[Patrick Caulfield]

On Fri, Dec 19, 2003 at 01:32:44PM +0100, Xavier Brouckaert wrote:
> Hi,
> 
> As the 2.6.0 is out, it's time for me to see if I can switch to it.
> What is the procedure and the things to know to switch from a 2.4 LVM1
> devfs to a 2.6 LVM2 udev ?  I'm using a debian/unstable.  I've seen that
> there was a package lvm2 (2.00.08-3) but the comment contains at the end
> "requires Linux kernel 2.4.". Does this mean that this package really
> cannot handle 2.6 kernels ?

No, that lvm2/devmapper packages handle 2.6 perfectly well. If you've got an
LVM1 setup on your Debian box all you should need to do to switch to LVM2 and
2.6.0 is install the lvm2 packages and reboot into the new kernel.

 
> I've also seen that devfs has been obsoleted by udev. However, I didn't
> find a udev package for sid nor a kernel option for it (but I've read
> that it is only in userspace).  The udev FAQ
> (http://www.kernel.org/pub/linux/utils/kernel/hotplug/udev-FAQ) does not
> mention if I need to install hotplug to have udev working.

I don't know about udev or hotplug. They are not required for LVM2/devmapper
operation though.
 
> Do I have to change something in /etc/lvmtab.d and /etc/lvmconf ?

No. lvm-common will detect whether you have device-mapper or LVM1 in the kernel
and use the appropriate LVM tools.
 
> It seems that a thing called "device-mapper" is needed, but I couldn't
> find it in the kernel. Is it CONFIG_DM_IOCTL_V4 ? The "DM" substring
> makes me think it's that but the comment in "make menuconfig" doesn't
> say that it's for LVM nor that it's a device mapper.

Yes, you must compile in IOCTL_V4 support for device-mapper in 2.6.0. (actually
I think that may have been fixed now but the old "V1" ioctls are deprecated).
CONFIG_BLK_DEV_DM is the device-mapper string but if you don't select that you
won't even see the option for IOCTL_V4 !


-- 

patrick