Dynamic Root Disk: Quick Start & Best Practices

Using DRD to Expand LVM Logical Volumes and File

Systems

Extending Files Systems Other Than /stand or /

One of the difficulties in expanding file systems in the root volume group of an LVM-based system is

that the file systems are always busy, so a boot to LVM maintenance mode is often needed to

complete the size change.

Because the entire inactive image created by a drd clone command is not in use, the system

administrator has an opportunity to expand file systems on the inactive image.

The following steps work for file systems other than the boot (/stand) file system.

1. After creating the clone, execute the command:

# /opt/drd/bin/drd mount

2. Choose the file system on the clone to expand. For this example, we are using /opt. The logical

volume is /dev/drd00/lvol6 mounted at /var/opt/drd/mnts/sysimage_001/opt. The

size of the vxfs file system is increased to 999 extents. Execute the following commands to

expand /opt:

# /usr/sbin/umount /dev/drd00/lvol6

# /usr/sbin/lvextend -l 999 /dev/drd00/lvol6

# /usr/sbin/extendfs -F vxfs /dev/drd00/rlvol6

# /usr/sbin/mount /dev/drd00/lvol6 \ /var/opt/drd/mnts/sysimage_001/opt

3. Run bdf to check that the /var/opt/drd/mnts/sysimage_001/opt file system now has the

desired size.

Extending the /stand or / File System

Note: Extending the root (“/”) file system is very similar to extending the /stand file system. For

brevity, we simply refer to the /stand file system in this section.

Overview

It can be a challenging task for a system administrator to increase the size of the /stand file system,

even in a Logical Volume Manager (LVM) environment. Because it is used by the boot loader,

/stand must be the first file system on a physical disk and it must be contiguous and non-relocatable.

Extents added to /stand must therefore come from the second logical volume on the disk, which, in

a “standard” configuration, is usually the swap area (and, fortuitously, is also contiguous). Typically,

it takes one reboot to free up swap space by moving to a new swap logical volume, and then another

reboot to switch to the larger /stand.