19. Dangerous Operations

Don't do this unless you're really sure of what you're doing. You'll probably lose all your data.

19.1 Restoring the VG UUIDs using uuid_editor

If you've upgraded LVM from previous versions to early 0.9 and 0.9.1 versions of LVM and ``vgscan'' says vgscan -- no volume groups found, this is one way to fix it.

• Download the UUID fixer program from the contributor directory at Sistina. It is located at ftp://ftp.sistina.com/pub/LVM/contrib/uuid_fixer-0.3-IOP10.tar.gz
• Extract uuid_fixer-0.3-IOP10.tar.gz

  # tar zxf uuid_fixer-0.3-IOP10.tar.gz
  

• cd to uuid_fixer

  # cd uuid_fixer
  

  You have one of two options at this point
  1. Use the prebuild binary (it is build for i386 architecture). Make sure you list all the PVs in the VG you are restoring, and follow the prompts

     # ./uuid_fixer <LIST OF ALL PVS IN VG TO BE RESTORED>
     

  2. Build the uuid_builder program from source Edit the Makefile with your favorite editor, and make sure LVMDIR points to your LVM source. Then run make.

     # make
     

     Now run uuid_fixer. Make sure you list all the PVs in the VG you are restoring, and follow the prompts.

     # ./uuid_fixer <LIST OF ALL PVS IN VG TO BE RESTORED>
     

• Deactivate any active Volume Groups (optional)

  # vgchange -an
  

• Run vgscan

  # vgscan
  

• Reactivate Volume Groups

  # vgchange -ay