I noticed that one of our CX4s was exhibiting some odd behaviour the other day. When looking at the System Information window, I noticed that FAST Cache seemed broken. Here’s a picture of it.
Going to the FAST Cache tab on System Properties yielded the same result, as did the output of naviseccli (using naviseccli -h IPaddress cache -fast -info). Interestingly, though, it was still showing up with dirty pages.
We tried recreating it, but the 8 * 100GB EFDs we were using for FAST Cache weren’t available. So we logged a call, and after a bit of back and forth with support, worked out how to fix it. A few things to note first though. If support tell you that FAST Cache can’t be used because you’re using EFDs, not SSDs, ask to have the call escalated. Secondly, the solution I’m showing here fixes the specific problem we had. If you frig around with the tool you may end up causing yourself more pain than it’s worth.
So, to fix the problem we had, we needed to log in to the /debug page on the CX4. To do this, go to http://<yourSPaddress>/debug.