[Crash-utility] determining a "valid" vmcore

hello, I'm looking at a customer issue where diskdumpmsg is unable to read a vmcore file. It is not clear if this a problem with the vmcore file or diskdumpmsg. I can load the vmcore with crash and in my naive usage of it, can see no problems. However, I'm new to the tool so that doesn't give me a lot of confidence. Does anyone have any suggestions on how or if I can use crash to help determine if there's corruption in the vmcore file? Or any other way of approaching the problem? Thanks much, Andrew