Recently, we have experienced a failed NEXSAN RAID controller in our Production environment. For those that do not know what is a NEXSAN RAID controller, it is a broad or component that is inside your SAN device that control the SAN’s RAID setup. Lucky when we brought this NEXSAN device, it is setup with a duel controllers system. Meaning it has two RAID controllers. All of our LUNs and VMs connection were able to fail over to the second controller in the SAN. If you never experienced a controller failure on your SAN, I can tell you it wasn’t fun. Especially when all of your production servers are on this SAN. So make sure to ALWAYS have redundant controller, power supply, etc… Otherwise, you might regard it when things break and fail on you.
To replace a failed NEXSAN controller, you would need to call NEXSAN support. So make sure your hardware is under warranty. Once you have called NEXSAN, they will open a ticket and send you the replacement part. A technician will contact you and will be also on site to help you install and replace the failed controller. The tech will pretty much just take out the old one and replace it with a new one. The new controller will go through a booting cycle and if successful it will turn green and you will be happy. You can sleep better too.
You can also visit NEXSAN FAQ section for more information on how to replace a controller in your environment.
Below is the link to NEXSAN FAQ section:
NEXSAN PDF instructions on how to change a controller