CentOS

I try to boot on my centos 7 but yesterday i saw this after the instalation of KVM. KVM was installed on the centos market not by commnads. This thing is theres no dev/mapper/centos-root seems like the partition was deleted or something. Warning: /dev/root does not exist
Generating "/run/initramfs/rdsosreport.txt"

What is "the centos market"?

Does it boot if you select an older kernel?