Chapter 2. Using EVMS to Manage Devices / 2.2. Configuring an Existing System Device to Use EVMS
	Chapter 2. Using EVMS to Manage Devices		2.3. Configuring LVM Devices to Use EVMS

Configuring an Existing System Device to Use EVMS

If you have already installed Linux with a different volume manager for the system device (that is, the devices where you installed the /boot, swap, or root (/) partitions), you can optionally configure the device for EVMS at any time after the install.

If you do not configure the device to use EVMS, you must manage the device and all of its volumes with its current volume manager (the default is LVM), and free space on the device cannot be used for volumes you want to create using EVMS. Beginning with the Linux 2.6 kernel, a given device cannot be managed by multiple volume managers. However, you can have different volume managers for different devices.

The following procedures assume that you installed Linux with three partitions on a single SCSI device named sda:

/dev/sda1  reiserfs /boot

/dev/sda2  swap     swap

/dev/sda3  reiserfs /

	Important
Make sure to modify the following procedures as necessary for your specific setup.

Disable the boot.lvm and boot.md Services

You need to disable boot.lvm (handles devices for Linux Volume Manager) and boot.md (handles multiple devices in software RAIDs) so they do not run at boot time. In the future, you want boot.evms to run at boot time instead.

In YaST, click System > Runlevel Editor > Expert Mode.
Select boot.lvm.
Click Set/Reset > Disable the Service.
Select boot.md.
Click Set/Reset > Disable the Service.
Click Finish, then click Yes.
The changes do not take effect until the server is restarted. Do not restart at this time.
Continue with Section 2.2.2, “Enable the boot.evms Service”.

Enable the boot.evms Service

You need to enable the boot.evms service so that it boots devices when you restart the server.

In YaST, click System > Runlevel Editor > Expert Mode.
Select boot.evms.
Click Set/Reset > Enable the Service.
The B runlevel option is automatically selected.

Click Finish, then click Yes.

The changes do not take affect until the server is restarted. Do not restart at this time.

	Note
Effective in SUSE Linux Enterprise 10, the `/dev` directory is on `tmpfs` and the device nodes are automatically re-created on boot. It is no longer necessary to modify the `/etc/init.d/boot.evms` script to delete the device nodes on system restart as was required for previous versions of SUSE Linux.

Continue with Section 2.2.3, “Edit the /etc/fstab File”.

Edit the /etc/fstab File

When you boot the system, the kernel reads the /etc/fstab file to identify which file systems should be mounted and then mounts them. This file contains a table of file system information about the /boot, swap, and root (/) partitions plus other partitions and file systems you want to mount.

You must edit the /etc/fstab file to modify the mount location of these three partitions so they are mounted under the /dev/evms directory. For example, change /dev/sda1 to /dev/evms/sda1.

Although the /boot partition is not managed by EVMS, the boot.evms script forces EVMS to scan all the partitions at boot time, including the /boot partition, and it activates /boot under the /dev/evms directory. Therefore, this makes /boot a partition that is discovered by EVMS at startup, and requires that the device’s path be listed under /dev/evms in the fstab file so it can be found when booting with boot.evms.

Make sure to replace sda1, sda2, and sda3 with the device names you used for your partitions.

	Important
When working in the `/etc/fstab` file, do not leave any stray characters or spaces in the file. This is a configuration file, and it is highly sensitive to such mistakes.

Open the /etc/fstab file in a text editor.
Locate the line that contains the /boot partition.
For example, if your /boot partition uses device sda1 and the Reiser file system, look for a line similar to this:
```
/dev/sda1 /boot reiser defaults 1 1
```
In the Device Name column, modify the mount location of the /boot partition from /dev to /dev/evms so it can be managed by EVMS. Modify only the device name by adding /evms to the path:
/dev/evms/sda1 /boot reiser defaults 1 1
Repeat Step 2 and Step 3 to edit the Device Name entry in the lines for the swap and root (/) partitions.
For example, change /dev/sda2 to /dev/evms/sda2, and change /dev/sda3 to /dev/evms/sda3.
Save the file.
The changes do not take effect until the server is restarted. Do not restart at this time.
Continue with Section 2.2.4, “Edit the Boot Loader File”.

Edit the Boot Loader File

When you boot the system, the kernel reads the boot loader file for information about your system. For Grub, this is the /boot/grub/menu.1st file. For LILO, this is the /etc/lilo.conf file.

You must edit the boot loader file to modify the mount location of partitions so they are mounted under the /dev/evms directory. For example, change /dev/sda1 to /dev/evms/sda1. Make sure to replace the path for all lines that contain device paths in the files. You can modify the boot loader file by editing fields in YaST, or use a text editor to modify the file directly.

	Important
When working in the boot loader file, do not leave any stray characters or spaces in the file. This is a configuration file, and it is highly sensitive to such mistakes.

Using YaST

To modify the boot loader file in the YaST Control Center:

Log in as the root user or equivalent.
In Yast, select System+Boot Loader.
Modify the boot loader image so that the root file system is mounted as /dev/evms/ instead of /dev/.
1. Select the boot loader image file, then click Edit.
2. Edit the device path in the Root Device field.
  For example, change the Root Device value from
  /dev/sda2
  to
  /dev/evms/sda2
  Replace sda2 with the actual device on your machine.
3. Edit any device paths in the Other Kernel Parameters field.
4. Click OK to save the changes and return to the Boot Loader page.
Modify the failsafe image so that the failsafe root file system is mounted as /dev/evms/ instead of /dev/.
1. Select the failsafe image file, then click Edit.
2. Edit the device path in the Root Device field.
3. Check the Other Kernel Parameters field and make changes if needed.
4. Click OK to save the change and return to the Boot Loader page.
Click Finish.
Continue with Section 2.2.5, “Force the RAM Disk to Recognize the Root Partition”.

Using a Text Editor

To edit the boot loader file in a text editor:

Log in as the root user or equivalent.
Open the boot loader file in a text editor.
For Grub, this is the /boot/grub/menu.1st file. For LILO, this is the /etc/lilo.conf file.
Locate the line that contains the root= parameter.
For example, if your root file system uses device sda1, look for a line similar to this:
```
kernel (sd0,0)/vmlinuz root=/dev/sda1 vga=0x31a splash=silent showopts
```
Modify the mount location from /dev to /dev/evms so it can be managed by EVMS.
For example, after the change, the line looks like this:
```
kernel (sd0,0)/vmlinuz root=/dev/evms/sda1 vga=0x31a splash=silent showopts
```
Repeat Step 3 and Step 4 to locate other lines in the file that need to be similarly modified.
Save the file.
The changes do not take effect until the server is restarted. Do not restart at this time.
Continue with Section 2.2.5, “Force the RAM Disk to Recognize the Root Partition”.

Force the RAM Disk to Recognize the Root Partition

The mkinitrd(8) command creates file system images for use as initial RAM disk (initrd) images. These RAM disk images are often used to preload the block device modules (SCSI or RAID) needed to access the root file system.You might need to force the RAM to update its device node information so that it loads the root (/) partition from the /dev/evms path.

	Note
Recent patches to mkinitrd might resolve the need to do this task. For the latest version of mkinitrd, see Recommended Updates for mkinitrd at the Novell Technical Support Center.

At a terminal console prompt, enter the EVMS Ncurses command as the root user or equivalent:
```
evmsn
```
Review the output to verify that EVMS shows only the /boot and swap partitions as active in EVMS.
You should see the following devices mounted (with your own partition names, of course) for these two partitions:
```
/dev/evms/sda1
```
```
/dev/evms/sda2
```
At a terminal console prompt, enter the following to update the initrd image with the /dev/evms path information for the root (/) partition:
```
/sbin/mkinitrd -f evms
```
This does not take effect until you restart the server.
Continue with Section 2.2.6, “Restart the Server”.

Restart the Server

Restart the server to apply the post-install configuration settings.
When your system restarts, the kernel loads the init-ramdisk, which runs the EVMS tools to activate your volumes and mount your root file system. Then your boot scripts run the EVMS tools once more to make sure your /dev/evms/ directory correctly reflects the current state of your volumes. Finally, the remaining EVMS volumes are mounted as specified in your /etc/fstab file. Everything else on your system should start up as you would normally expect.
Continue with Section 2.2.7, “Verify that EVMS Manages the Boot, Swap, and Root Partitions”.

Verify that EVMS Manages the Boot, Swap, and Root Partitions

At a terminal prompt, enter the EVMS Ncurses command as the root user or equivalent:
```
evmsn
```
Review the output to verify that EVMS shows the /boot, swap, and root (/) partitions as active in EVMS.
You should see the following devices mounted (with your own partition names, of course) under the /dev/evms directory:
```
/dev/evms/sda1
```
```
/dev/evms/sda2
```
```
/dev/evms/sda3
```