In this post, I have explained AWS (Amazon Web Services) tricky interview questions. The EBS, AMI, S3 and Amazon instance included in my questions Q1. Explain Elastic Block Storage? What type of performance can you expect? How do you back it up? How do you improve performance? A1. EBS is a virtualized SAN or storage area network. That means it is RAID storage to start with so it’s redundant and fault-tolerant. If disks die in that RAID you don’t lose data. Great! It is also virtualized, so you can provision and allocate storage, and attach it to your server with various API calls. No calling the storage expert and asking him or her to run specialized commands from the hardware vendor.   Performance on EBS can exhibit variability . That is it can go above the SLA performance level, then drop below it. The SLA provides you with an average disk I/O rate you can expect. This can frustrate some folks especially performance experts who expect reliable and consistent disk thr...