Has anyone tried to update a Fedora 20 Linode to Fedora 21, successfully or otherwise? I have done this successfully on a local install of Fedora 20, but the first Linode I tried failed with the following error.

# fedup --network 21 --product=nonproduct          
setting up repos...
... 
testing upgrade transaction
rpm transaction 100% [===========================================================================================================================================]
rpm install 100% [===============================================================================================================================================]
setting up system for upgrade
Traceback (most recent call last):
  File "/usr/bin/fedup", line 286, in <module>
    main(args)
  File "/usr/bin/fedup", line 223, in main
    prep_boot(kernel, initrd)
  File "/usr/lib/python2.7/site-packages/fedup/sysprep.py", line 168, in prep_boot
    customize_initrd(initrd)
  File "/usr/lib/python2.7/site-packages/fedup/sysprep.py", line 139, in customize_initrd
    wantfiles = fnmatch.filter(curimg, "etc/*")
  File "/usr/lib64/python2.7/fnmatch.py", line 58, in filter
    for name in names:
  File "/usr/lib/python2.7/site-packages/fedup/boot.py", line 108, in __iter__
    return iter(self.listfiles())
  File "/usr/lib/python2.7/site-packages/fedup/boot.py", line 74, in listfiles
    self._files = self.cpio("--list").splitlines()
  File "/usr/lib/python2.7/site-packages/fedup/boot.py", line 69, in cpio
    stdin=self.decomp().stdout)
  File "/usr/lib/python2.7/site-packages/fedup/boot.py", line 60, in decomp
    self._decomp = decomp_cmd(self.img)
  File "/usr/lib/python2.7/site-packages/fedup/util.py", line 107, in decomp_cmd
    header = open(filename, 'rb').read(6)
IOError: [Errno 2] No such file or directory: '/boot/initramfs-3.15.4-x86_64-linode45.img'

I'm getting a similar error going from Fedora 19 to 20. Any new on this?

Using Yum to upgrade worked fine for Fedora 19 to 20 and 20 to 21. There is an easily searchable guide on line.

Not an answer to the question, but this is why I use CentOS instead of Fedora.

Fedora's lifespan is too short, and while upgrading can usually be made to work, it is often a pain.