I have some RHEL6 hypervisors and the VMs are in raw qemu image files in a local raid array linux raid + lvm + ext3. When a kernel update is installed a reboot is necessary, usually it has been more than 180 days since the last reboot and the file system is fsck'd and this takes 2-3 hours. 

I am curious to know if there is any documentation that addresses the pro's and con's of fsck'ing the volume containing /var/lib/libvirt/images.

Could fsck make a change to the underlying file system that the guest images are stored on, which the guest operating system may not be able to handle when it runs its own file system maintenance, i.e. fsck or chkdsk. 

Is file system maintenance on the hypervisor volume storing the VM images redundant to the VM's own file system consistancy utilities.

Regards,

Jamie Ian Fargen