Hi, A few days ago we received a support ticket from a customer who had upgraded to Debian unstable and found that their kernel no longer booted. Upon further investigation, starting with Debian jessie (testing), Debian has switched to compressing their kernels with XZ as opposed to GZIP. The version of Xen hypervisor we are running does not currently support XZ decompression of kernels, so if you tried to boot one you would receive a message like: Error: (2, 'Invalid kernel', 'xc_dom_find_loader: no loader found\n') and be returned to Xen Shell. I have some ideas about workarounds for this, so if anyone else is experiencing this issue could I ask that you please contact support(a)bitfolk.com and we'll try some things out. - How to tell what compression method your kernel uses $ grep CONFIG_KERNEL_ /boot/config-* /boot/config-2.6.32-5-686-bigmem:CONFIG_KERNEL_GZIP=y /boot/config-2.6.32-5-686-bigmem:# CONFIG_KERNEL_BZIP2 is not set /boot/config-2.6.32-5-686-bigmem:# CONFIG_KERNEL_LZMA is not set /boot/config-3.2.0-3-686-pae:CONFIG_KERNEL_GZIP=y /boot/config-3.2.0-3-686-pae:# CONFIG_KERNEL_BZIP2 is not set /boot/config-3.2.0-3-686-pae:# CONFIG_KERNEL_LZMA is not set /boot/config-3.2.0-3-686-pae:# CONFIG_KERNEL_XZ is not set /boot/config-3.2.0-3-686-pae:# CONFIG_KERNEL_LZO is not set /boot/config-3.2.0-4-686-pae:CONFIG_KERNEL_GZIP=y /boot/config-3.2.0-4-686-pae:# CONFIG_KERNEL_BZIP2 is not set /boot/config-3.2.0-4-686-pae:# CONFIG_KERNEL_LZMA is not set /boot/config-3.2.0-4-686-pae:# CONFIG_KERNEL_XZ is not set /boot/config-3.2.0-4-686-pae:# CONFIG_KERNEL_LZO is not set These are all GZIP. CONFIG_KERNEL_XZ would be the only one set if XZ was used. So far I am only aware of Debian jessie and beyond switching to XZ, but there may be others I am not aware of. Once I have worked out a suitable workaround I will document it but most likely it can be sorted out on BitFolk's side so you won't notice. Cheers, Andy -- http://bitfolk.com/ -- No-nonsense VPS hosting