----- "Alex Sidorenko" <asid(a)hp.com&gt; wrote: I'm not sure I completely understand, but there shouldn't be any reference at all in your System.map file to any kernel module symbols, i.e, it should only contain symbols from the vmlinux file. So the System.map file should have no bearing upon the change in the nfsd module's "lru_head" address. What has happened is that the original "lru_head" address of f908b988 came from the address that was exported to the kernel from the nfsd.ko module when the module was insmod'd. (i.e., having nothing to do with the crash utility) Then the crash utility was then brought up, and it found that f908b988 address was exported to the kernel via the "good" nfsd.ko module structure data. The first "sym lru_head" command shows that address. However, then you loaded (via an internal "add-symbol-file" gdb operation) the older nfsd.ko module's information into the crash utility -- and it overwrote the original symbol value data with that from the (non-matching) nfsd.ko that contains the incorrect f908b984 address. So the crash utility is just doing what you told it to do. There's no support for loading a module that doesn't match reality, and continuing to use the old (correct) symbol addresses. Dave