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Setting up a VxVM root disk and mirror

To set up a VxVM root disk and a bootable mirror of this disk, use the vxcp_lvmroot utility. This command initializes a specified physical disk as a VxVM root disk named rootdisk## (where ## is the first number starting at 01 that creates a unique disk name), copies the contents of the volumes on the LVM root disk to the new VxVM root disk, optionally creates a mirror of the VxVM root disk on another specified physical disk, and make the VxVM root disk and its mirror (if any) bootable by HP-UX.

Only create a VxVM root disk if you also intend to mirror it. There is no benefit in having a non-mirrored VxVM root disk for its own sake.

Warning: These procedures should be carried out at init level 1.

The following example shows how to set up a VxVM root disk on the physical disk c0t4d0:

# /etc/vx/bin/vxcp_lvmroot -b c0t4d0

The -b option to vxcp_lvmroot uses the setboot command to define c0t4d0 as the primary boot device. If this option is not specified, the primary boot device is not changed.

If the destination VxVM root disk is not big enough to accommodate the contents of the LVM root disk, you can use the -R option to specify a percentage by which to reduce the size of the file systems on the target disk. (This takes advantage of the fact that most of these file systems are usually nowhere near 100% full.) For example, to specify a size reduction of 30%, the following command would be used:

# /etc/vx/bin/vxcp_lvmroot -R 30 -v -b c0t4d0

The verbose option, -v, is specified to give an indication of the progress of the operation.

The next example uses the same command and additionally specifies the -m option to set up a root mirror on disk c1t1d0:

# /etc/vx/bin/vxcp_lvmroot -m c1t1d0 -R 30 -v -b c0t4d0

In this example, the -b option to vxcp_lvmroot sets c0t4d0 as the primary boot device and c1t1d0 as the alternate boot device.

This command is equivalent to using vxcp_lvmroot to create the VxVM-rootable disk, and then using the vxrootmir command to create the mirror:

# /etc/vx/bin/vxcp_lvmroot -R 30 -v -b c0t4d0

# /etc/vx/bin/vxrootmir -v -b c1t1d0

The disk name assigned to the VxVM root disk mirror also uses the format rootdisk## with ## set to the next available number.

The target disk for a mirror that is added using the vxrootmir command must be large enough to accommodate the volumes from the VxVM root disk.

Once you have successfully rebooted the system from a VxVM root disk to init level 1, you can use the vxdestroy_lvmroot command to completely remove the original LVM root disk (and its associated LVM volume group), and re-use this disk as a mirror of the VxVM root disk, as shown in this example:

# /etc/vx/bin/vxdestroy_lvmroot -v c0t0d0

# /etc/vx/bin/vxrootmir -v -b c0t0d0

You may want to keep the LVM root disk in case you ever need a boot disk that does not depend on VxVM being present on the system. However, this may require that you update the contents of the LVM root disk in parallel with changes that you make to the VxVM root disk.

See "Creating an LVM root disk from a VxVM root disk" on page 106.

See the vxcp_lvmroot(1M) manual page.

See the vxrootmir(1M) manual page.

See the vxdestroy_lvmroot(1M) manual page.

See the vxres_lvmroot (1M) manual page.