[linux-lvm] creating a snapshot

[linux-lvm] creating a snapshot

[Bill Ranck]

Hello folks,
   I have been trying to create a snapshot of a filesystem on a RHEL AS4
system.  Here is the command line and the error message:

# lvcreate --size 100m --snapshot --name snap01 /dev/HDVL/db01
  snapshot: Required device-mapper target(s) not detected in your kernel

I copied the example right out of the man page.  I'm not sure what it
means that the device-mapper target is not detected in the kernel.  Can
anyone point me in the right direction here?

-- 
Bill Ranck
Blacksburg, Va.
540-231-3951

Re: [linux-lvm] creating a snapshot

[Alasdair G Kergon]

On Wed, Oct 19, 2005 at 12:53:21PM -0400, Bill Ranck wrote:
>   snapshot: Required device-mapper target(s) not detected in your kernel

modprobe dm-snapshot
 
There's an untested fix for this in CVS now.

Alasdair
-- 
agk@redhat.com

Re: [linux-lvm] creating a snapshot

[Bill Ranck]

On Wed, 2005-10-19 at 17:56 +0100, Alasdair G Kergon wrote:
> On Wed, Oct 19, 2005 at 12:53:21PM -0400, Bill Ranck wrote:
> >   snapshot: Required device-mapper target(s) not detected in your kernel
> 
> modprobe dm-snapshot

Thanks, that worked.  

> There's an untested fix for this in CVS now.

Huh?  Where/what is CVS?  Is this fix something up2date would grab?
Sorry, I'm fairly new to the Redhat way of doing things.


On a related topic, is there any way to create a snapshot outside of the
volume group containing the original target?  I'm short on space in the
original VG and would like the snapshot the use some other space in a
different VG.  If not, I'll have to shuffle some disk space around.

-- 
Bill Ranck
Blacksburg, Va.
540-231-3951