Administering disks 105

Rootability

Note: The -boption 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 -Roption 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.

Caution: 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.

The next example uses the same command and additionally specifies the -moption 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 -boption 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.

Note: 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