After installing 3 new hosts, I kept getting errors for Storage Connectivity stating “Lost path redundancy to storage device naa…….”. We had 2 fibre cards and one of the paths was being marked as down. I spent a couple weeks troubleshooting and trying different path selection techniques. Still, we would randomly get alerts that the redundant path has gone down. The only fix was to reboot the host, as not even a rescan would bring the path back up.
So after some trial and error, I found a solution. The RCA isn’t necessarily complete yet, but I believe it was a problem with the fibre switch having an outdated firmware and us using new fibre cards in our hosts. When using the path selection of Fixed, it would randomly pick an hba to use for each datastore. Some datastores would use path 2 and some would use path 4.
The solution I came up with was to manually set the preferred path on each datastore (we have about 40, so it was no easy task). You go into your host configuration, choose storage, pick a datastore and go into properties. Inside this window, select manage paths from the bottom right and you should see your HBA’s listed. There is a column marked Preferred with an asterisk showing which hba to prefer for the datastore (see the image below). I went through and manually set the preferred path to be hba2 instead of letting vmware pick the path. The path selection is persistent across reboot as well when setting it manually.
Since manually setting the preferred path, the hosts have been stable and we have not gotten any more errors about path redundancy. This is pretty much a band aid fix but at least we are not rebooting hosts 2-3 times per week.
I recently took and passed my VCP5-DCV (510) exam. To be honest, it wasn’t what I was expecting and there were other ways that I could have better prepared in hindsight. Hence the reason for this post, to share my experience with those preparing or thinking about taking the exam.
My first tip would be to have confidence going into the exam. If you’re thinking about or preparing to take the exam, then you already have experience with vCenter and virtualization. So walk into the test center like a boss and own that exam.
Second, take as many practice exams as you can find. I found a few that helped. A great site I found was here (mwpreston.net). VMware also has practice exams on their mylearn site. A tip for the mylearn site is if you get all the questions right, you can’t take it again. So you should purposely get some questions wrong so you can continue using it.
Third, if you can, build a lab and play with things you normally don’t use. Add some virtual iSCSI adapters if you don’t use iSCSI, etc. Be prepared and expect to see things on the test that you have never used before and use your best judgement to answer the questions.
Fourth and finally, read as much as you can. I’m sure we’ve all been in the situation of cramming for an exam. The night before, trying to read the entire textbook to suck as much knowledge out of it as possible. I would suggest giving yourself ample time to prepare and get comfortable with topics on vCenter, vDS and Standard Switches, and storage adapters.
With all that said, the first tip is the most important. Have the confidence you know this stuff and that you have prepared. Don’t second guess yourself when answering the questions and go with your gut feeling. Take the practice exams, study the basics, and pass!
Best of luck and if you have any other questions, drop me a line.