Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Administering a Workgroup
Managing Disks
Chapter 9866
Extending a Logical Volume When You Can’t Use SAM
Before you can extend a logical volume, you must unmount the file
system mounted to it. In the case of system directories, such as /var and
/usr, you will need to be in single-user mode to do this.
NOTE Extending the root (/) logical volume is a special case. You will not be able
to extend the root file system using the procedure described below. This
is because the current root file system cannot ever be unmounted as
required by extendfs. Thus, you will not be able to extend it even if you
shut down to single-user state.
To extend the current root file system, you will need to have created and
mounted another root disk. This allows you to work with the unmounted
original root disk, extending it if there is contiguous disk space still
available. If the original disk does not have contiguous disk space
available, instead of expanding the original root disk, you can create a
new root file system on another larger disk.
If you are using JFS as your root file system and have the OnLineJFS
product, you will be able to extend the original root file system without
unmounting provided there is contiguous disk space available.
See “Creating Root Volume Group and Root and Boot Logical Volumes”
on page 578 for additional information.
In the example that follows, we’ll extend /usr, which means we won’t be
able to use SAM, because SAM resides in /usr/sbin.
Let’s suppose you’ve been trying to update the system to a new HP-UX
release, and have seen the following error message in swinstall:
ERROR: The used disk space on filesystem "/usr" is estimated to
increase by 57977 Kbytes.
This operation will exceed the minimum free space
for this volume. You should free up at least 10854
Kbytes to avoid installing beyond this threshold of
available user disk space.
In this example, you need to extend the /usr volume by 10 MB, which
actually needs to be rounded up to 12 MB.
Step 1. Log in as root