Stuck in increasing the size of root partition by taking space from XEN LVM

Hi, I am stuck in pretty weird situation. I hope somebody here will help me.

I have one centOS server with XEN installed on it. XEN has 3-4 virtual machines running on it. As required by XEN, this server
has LVM implemented. The structure of Disk System is as following ( Kindly click on this image link) :

http://yfrog.com/72sh01nov191726j

This server has two disks of 750 GB each, and RAID implemented. MD2 partition is / (root) filesystem. It has only 10 GB of space. Now i have to increase the space of / filesystem. It is running short on space. Some more information about server is following:

1. It has 1 volume group named xen in its LVM and its size is 682 GB.
2. Their is a physical volume named md3 in volume group xen and its size is 682 GB.
3. This physical volume has 5 logical volumes which are used for XEN virtual machines.

This volume group has 400 GB of free disk space. So i want to extract some space (200 GB)from it and use this space for / (root) partition.root partition ( '/' ) is the boot partition and is holding all the system files of CentOS.
Output of pvdisplay is : img29.imageshack.us/i/sh02nov192131.jpg
output (shortened, its big list)lvdisplay is: img831.imageshack.us/i/sh03nov192132.jpg
output of mount is : img269.imageshack.us/i/sh04nov192132.jpg

I have webmin installed n this server along with hyperVM. In webmin i can see LVM and partitions. There is one option in which we can add any logical volume to any Raid device partition. Doyou think that will an good idea and risk free. Kindly look at the attachd screenshot yfrog.com/jysh05nov201208j

This is a live server and i can not take risk of testing some test methods on it. I have searched for 4-5 hours for this issue but i was not able to get the proper and authentic answer. So i thought i should post my question here so that i can get a authentic answer.

This is very urgent, my client is shouting on me. .

one more thing i have no physical access this server as it is located in another country.

Kindly help me to solve this.

 

If you want to increase the size of the / partition, you will have to boot into some kind of rescue system or live CD. This cannot be done while the / partition is mounted.

You could do it with GParted, I guess. These links might help as well:
http://www.howtoforge.com/linux_lvm
http://www.howtoforge.com/linux_resizing_ext3_partitions
http://www.howtoforge.com/how-to-resize-raid-partitions-shrink-and-grow-software-raid
http://www.howtoforge.com/how-to-resize-lvm-software-raid1-partitions-shrink-and-grow

 

Hi Falko,

Thanks for you reply. The only problem u have is that i do not have any physical access to my server. I understand that this thing may require physical access.
I have another thing in my mind. As i have written in the question, I have access to webmin and in webmin there is an option to add any logical volume to RAID partition. I can create logical volume from that interface. and after creating there is an option to add it to RAID partition. I have never tried this before. so i am not sure whether this is a good idea or not. Kindly suggest me if this is possible.

 

I don't think this will work. Do you have a rescue system on the server that you can boot into?