Adding a temporary REDO File to online VM with a script

It is possible to attach a temporary REDO file to a VM which is in a powered on state. Normally, you have to power down the VM to change the disk mode. In this case, the VM disk stays in a Persistent mode, but has a REDO file.
The REDO file is automatically committed to the virtual disk when you shutdown, unless you use vmware-cmd or vmkfstools to commit the REDO to the virtual disk beforehand. When you power up the virtual machine, the REDO file is not recreated

The Perl script that achieves this is available from VMware Support here:

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  1. Logon to the Service Console, as ROOT or VM Administrator
  2. Run nano -w addredo.pl
  3. Cut and Paste the script above into the window
  4. Close nano and save the file

     To use the script – follow this example below

    perl addredo.pl esx1.rtfm-ed.co.uk root password /root/vmware/instructor1/instructor1.vmx scsi0:0

    Syntax requirements can be viewed by simply typing  pl addredo.pl
    To use the script you must specify:

    Name of ESX server
    Username and Password
    Path to VMX file
    Optionally, specify the scsi node (in case your VM has more than one virtual disk – scsi0:0 adds a REDO to the boot disk)


This was first published in July 2005

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