how to change linux software raid md device name and lvm volume group name

     
 Sometimes you want to move a harddisk or a raid set to other linux machine. But you will find that the raid and lvm setting will have error. It prompt you that the md name and/or lvm name encounter problem due to same name.(normally it caused by the default installation.) You can change the md name and lvm name as below:


connect the old harddisk or raid set in a computer which is no other harddisk and  raid set.

--------------------------------------
change md name


start ubuntu live cd

apt-get install lvm2
if not yet installedin your ubuntu version

apt-get install mdadm
if not yet installedin your ubuntu version

Start with (assume your raid set is md127)

mdadm --detail /dev/md127

or if just only have incomplete raid set like one harddisk in raid 1.
(assume your harddisk partition is sda1)
mdadm --examine /dev/sda1

Version : 0.90

The first line or second line shows the metadata version used by this array. Now, stop the array:

mdadm --stop /dev/md127
mdadm --remove /dev/md127

And assemble it again using the new name. (metadata version is 1.0 or higher, use this:)

mdadm --assemble /dev/md3 /dev/sd[abcdefghijk]1 --update=name

For old metadata structure (most likely 0.90, as it allows for kernel auto-assembly), use this:

mdadm --assemble /dev/md3 --update=super-minor /dev/sd[abcdefghijk]1

-----------------------------------------
change vg name

boot linux rescue or ubuntu live cd/usb

in command prompt or terminal key in

lvm vgscan
lvm lvscan
lvm vgchange -a y
lvm pvscan
lvm lvscan

The last two commands should list your volume group(s) and logical volume(s). We use vgrename to change the name.

lvm vgrename VolGroup00 to-what-you-want-to-be