<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv=Content-Type content="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 11 (filtered medium)">  <style>  </style> </head> <body lang=EN-US link=blue vlink=blue> <div class=Section1> I appreciate the suggestion about using MD driver.<o:p></o:p> <o:p> </o:p> However, I have already built MD devices which are hosting the volume groups and logical volumes.<o:p></o:p> <o:p> </o:p> I am not aware of being able to using the MD driver with MD devices as opposed to non MD devices (mirroring a mirror rather then mirroring straight disk partitions).<o:p></o:p> <o:p> </o:p> Does any know if this is possible?<o:p></o:p> <o:p> </o:p> Thanks!<o:p></o:p> <o:p> </o:p> <div> <div class=MsoNormal align=center style='text-align:center'> <hr size=2 width="100%" align=center tabindex=-1> </div> From: linux-lvm-bounces@redhat.com [mailto:linux-lvm-bounces@redhat.com] On Behalf Of Jed Donnelley Sent: Monday, May 01, 2006 8:05 PM To: LVM general discussion and development Subject: Re: [linux-lvm] Cloning Logical Volumes<o:p></o:p> </div> <o:p> </o:p> At 03:21 PM 4/27/2006, Jonathan E Brassow wrote: <o:p></o:p> dd is probably the best way right now. in the future, the clone would probably take the form: prompt> lvconvert -m1 vg/lv; (wait for sync); lvsplit vg/lv The syntax isn't worked out yet and lvsplit is not there yet... but we have talked about doing something like that. brassow <o:p></o:p> One possibility that occurs to me is to use RAID-1 under LVM and then clone your LVM file system(s) by splitting a software RAID-1 clone (e.g. MD driver). Even if you don't want to pay the price of redundant disks in your final system configuration, you can leave it with a single 1/2 RAID set with no loss of reliability (over no RAID). You can even do the RAID-1ing on a single disk if that has any potential value, but it's a bit more difficult for me to see how you would separate the clone out that way. Just a thought. I use such RAID-1 cloning quite often and find it very convenient. It seems to me it would work fine in this case. About the only thing I find I have to be careful of is to be sure that if I'm cloning the /boot (or /root if it includes /boot) file system that I make sure the boot record is in place (in my case running grub and writing the appropriate record on the appropriate disk before splitting the RAID system for cloning). I still don't trust LVM for recovering munged file systems (no effective mechanism for fsck if you can't get to the LVM file system, init problems for RAID-10, etc. as mentioned previously on this list) so I'm not using LVM at this time and haven't tested the above mechanism. You're mileage may vary. <o:p></o:p> On Apr 26, 2006, at 5:55 PM, Greg Hartzog wrote: <o:p></o:p> Hello there folks. I have a question. I am looking for a better way of cloning logical volumes then creating a new logical volume, identical to a source logical volume, and using dd to copy data between the two logical volumes. I would love to use dm-mirror to do this, but I do not think any interface has been provided to do this yet. All suggestions and ideas appreciated. I am running lvm2-2.02.04-r1 & 2.6.15 kernel. Thanks! <o:p></o:p> </x-sigsep><x-sigsep>--Jed <a href="http://www.nersc.gov/~jed/" eudora=autourl>http://www.nersc.gov/~jed/</a><o:p></o:p> </div> </body> </html>