---
name: "uml_moo"
section: "1"
platform: "linux"
package: "uml-utilities"
version: "20070815.4-2.1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/uml_moo"
---

# uml\_moo(1)

merge a COW file with its backing file

## NAME

uml\_moo — merge a COW file with its backing file

## SYNOPSIS

**uml\_moo** \[*COW file*\]  \[*new\_backing\_file*\]

## DESCRIPTION

This manual page documents briefly the  **uml\_moo** command.

This manual page was written for the **Debian GNU/Linux** distribution  because the original program does not have a manual page.  Instead, it has documentation in HTML format; see below.

**uml\_moo** is a program to merge a COW  (copy-on-write) file with its backing file, and write the result  to a new backing file.  This can be used periodically to update  the backing file with the changes made in the COW file.

NOTE: you can save a lot of disk space using COW files.  When checking the size of the COW file in order to see the gobs  of space that you're saving, make sure you use 'ls -ls' to see the actual  disk consumption rather than the length of the file. The COW file is  sparse, so the length will be very different from the disk usage.

## SEE ALSO

The *UserModeLinux-HOWTO (link to URL http://user-mode-linux.sourceforge.net/UserModeLinux-HOWTO.html)*

## AUTHOR

uml\_moo was written by RidgeRun,Inc  glonnon@ridgerun.com

This manual page was written by Matt Zimmerman mdz@debian.org for  the **Debian GNU/Linux** system, based on material in the  UserModeLinux-HOWTO by Rusty Russell.