Often times, users want to migrate their storage because the system was originally installed on a single filesystem built onto a partition. In this how-to, we will also break up the root filesystem into multiple filesystems for greater flexibility and performance. This storage configuration also makes the system less vunerable to catastrophic failure.

To ensure we create each filesystem with enough space, we need to document how much space is being taken up.

This will list the amount of space used in each directory in the root filesystem. We are most concerned with /boot /usr /var /home and /opt. The remaining directories will be a part of the root filesystem. In your case, you might want to make the storage more or less granular.

This how-to assumes you already know how to create a backup job. If not, please see the SBAdmin Users Guide for more information.

1. Create a backup using a full system backup type profile (ie. FULL_SYSTEM) to tape, remote server, or external disk.
2. Create SBAdmin installation boot media. (For more information see the SBAdmin Linux System Recovery Guide)

Power-on the system and press the key combination to enter the BIOS or a boot menu to select the device to boot your installation boot media. (CDROM, network adapter, external disk/USB drive)

Once the system is booted you will be presented with the Installation Menu

( Main Menu )

Select the installation device  (may require network configuration) and select the backup to restore from. Once you have selected the backup, press F3 or ESC until you are back at the Main Menu.

From the Main Menu, select View/Change Installation Settings, and then Change Partition Tables

( Edit Partition Table )

Your configuration may differ, but in this case, there are two partitions. One partition is used for swap and the other partition is used for the root (/) filesystem. The partitions are taking up the entire space on the disk.

When we finish, we will have three partitions – /boot (sda1) swap (sda2) and the physical volume (PV) for the volume group (VG) (sda3).

1. The first step is to add two additional partitions to be used by the /boot filesystem.
2. Select Add New Partition and add one 54MB partition of type 83 at the beginning of the disk (sda1) and one 54MB at the end of the disk (sda5). This becomes sda5 due to the need for an extented partition. Don’t worry, we will still end up with 3 partitions in the end.
3. Select the partition currently being used for the root filesystem (sda3).
4. Change the parition type from 83 (Linux) to 8e (Linux LVM) and reduce the size by 54MB.
5. Press F3/ESC once to return back to the Change Installation Settings Menu. (You can ignore the errors you see regarding the disk space usage – for now)
6. We need to move the root filesystem off of its current partition (sda3) and move it to the last partition (sda5).CONFUSION WARNING!!
   SBAdmin has a safety precaution that prevents you from removing or repurposing the device the root filesystem is using. We need to move the root filesystem off to another partition temporarily before moving it to a logical volume. We will use the sda5 temporarily, then move it to a logical volume once we have created it.
7. Select Add or Change Filesystems
8. Select the root filesystem and change the “Device” to the last partition (sda5). Press F3/ESC to save the configuration.
9. Select Add New and create a new /boot filesystem on the first partition (sda1). Press F3/ESC to save the configuration.

Now we are ready to set up our LVM environment.

1. From the Change Installation Settings Menu, select Logical Volume Management
2. Select Add or Remove Physical Volumes
3. Use the up/down arrows and press [enter] to select the partition previously used by the root filesystem (sda3). Press F3/ESC once to return to the LVM menu.
4. Select Add or Change Volume Groups, select Add New
   
   ( Create/Edit Volume Group )
5. From this screen you configure your volume group. In this example we will use the name “rootvg”. This is the name typically used on AIX and HP-UX systems. Press F3/ESC when finished. Also, we will use the physical volume sda3.
6. Select Add or Change Logical Volumes, select Add New
   
   ( Create/Edit Logical Volumes )
7. From this screen you configure your logical volumes. In this example, create the following logical volumes:
   

   Logical Volume	Size in MB	Physical Volume
   rootlv	1536	sda3
   homelv	4096	sda3
   usrlv	3072	sda3
   varlv	1024	sda3
   optlv	256	sda3

   It is a good idea to name the logical volumes similar to the fileysystems they will contain. For some reason Linux distributions like to name them lv01, lv02, etc. This is harder to keep track.

8. Press F3/ESC twice to return to the Change Installation Menu.

Change/Create Filesystems

1. From the Change Installation Settings Menu, select Add/Change Filesystem
2. From this screen you can create and configure each new filesystem. You can use the defaults or make changes such as the filesystem type. Create the following filesystems:

   Name	Device
   /boot	sda1
   /home	homelv
   /usr	usrlv
   /var	varlv
   /opt	optlv

3. Once you have created each of the above filesystems, select the root filesystem. Edit the device used from the 64M partitions you recently created to the new “rootlv” logical volume. Press F3/ESC twice to return to the Change Installation Settings Menu. (You can ignore the warning about space because we will be spreading the data across multiple filesystems.)

Final Cleanup and Restore

As I stated before, we will remove the temporary partition we created. From the Change Installation Settings Menu, select Change Partition Tables
Select to remove the last partition (sda5). Once it is removed you should have three partitions.

Partition	Type	Contents
sda1	Linux	/boot
sda2	Swap	Swap Device
sda3	LVM	VG:rootvg