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37.4. Manually loading the para-virtualized drivers

If for some reason the para-virtualized drivers failed to load automatically during the boot process you can attempt to load them manually.
This will allow you to reconfigure network or storage entities or identify why they failed to load in the first place. The steps below should load the para-virtualized driver modules.
First, locate the para-virtualized driver modules on your system. 
# cd /lib/modules/`uname -r`/
# find . -name 'xen_*.ko' -print
Take note of the location and load the modules manually. Substitute {LocationofPV-drivers} with the correct location you noted from the output of the commands above. 
# insmod \
/lib/modules/'uname -r'/{LocationofPV-drivers}/xen_platform_pci.ko
# insmod /lib/modules/'uname -r'/{LocationofPV-drivers}/xen_balloon.ko
# insmod /lib/modules/'uname -r'/{LocationofPV-drivers}/xen_vnif.ko
# insmod /lib/modules/'uname -r'/{LocationofPV-drivers}/xen_vbd.ko