difference between dmesg and /var/log/kern.log

Question

I am modifying the kvm module and I have added printk statements in the kernel code.After running the virtual machine, printk gives me the faulting address and other informatio

Answer 1

/var/log/kern.log and his rotated logs (/var/log/kern.log.1 /var/log/kern.log.2....) contains the logs produced by the kernel and handled by syslog.

dmesg as explained by the man page is for :

dmesg is used to examine or control the kernel ring buffer.

In fact, it will display the last 16392 octets of /var/log/kern.log since last boot.