3 Replies Latest reply: Aug 27, 2015 1:24 PM by Daniel Duffy RSS

    Power Outage Control?

    LFM Support Newbie

      We are running a few CS220 appliances and had a question regarding unplanned power outages and how to handle them. We have big beefy UPSs and our plan is to shut all servers and important appliances when there is X amount of run time remaining. We have configured our servers and it works perfectly but we don't quite know what to do with the CS220s. I've spoken with Support and they say that if there is no I/O on the appliance because the VMs running on the volumes have been shutdown then it is safe to let the appliance go down hard. I'm not a fan of letting hardware go down like that so is there another way to justify doing this? For example, is there a big capacitor which allows for flushing the writers when a controller loses power? Is there some built-in mechanism which prevents data loss/corruption when power is lost?
      Thanks in advance.

        • Re: Power Outage Control?
          Peter Evans Wayfarer

          The system has an NVDIMM module that contains any uncommitted writes.  Its contents are also mirrored to the NVDIMM in the standby controller.  NVDIMM is a combination of supercapacitor backed DRAM and Flash memory.  In the event of a power outage, the contents of the DRAM are destaged to the flash component of the module.  You don't have the traditional time limit of a few days to restore power.  It is persistent storage.  When you power up the system again, any writes in the NVDIMM will be destaged to disk.

           

          A graceful shutdown might have the minor advantage that the subsequent startup could be a little faster but your data is protected either way.

           

          If you really want to ensure a clean shutdown, how about a script to connect to the array and power it down after all the servers have been shut down?