+++ This bug was initially created as a clone of Bug #635266 +++

In the original bug report, the kernel problem causes
the appliance to crash.  This means virt-df cannot complete
the full scan of guests:

$ sudo virt-df -h
Filesystem                                Size       Used  Available  Use%
FedoraRawhidex64:/dev/sda1              484.2M      47.0M     412.2M   10%
FedoraRawhidex64:/dev/vg_f13x64/lv_root
                                          7.4G       2.8G       4.5G   39%
Minix3x32:/dev/sda5                      62.0M       5.3M      56.7M    9%
Minix3x32:/dev/sda6                     779.6M        60K     779.5M    1%
umount_all: call launch before using this function
(in guestfish, don't forget to use the 'run' command) at /usr/bin/virt-df line 353.

[there are more guests after this one]

virt-df should have a mode where it launches one
appliance per guest (as it used to do) which can be used
to work around this issue.

At the same time, reduce max drives to 25.