On 1 August 2016 at 07:30, Dũng Trần-Dương <chris.duong83 at gmail.com> wrote: > Hi, > > I launched an AWS instance `t2.medium` (use CentOS 7 image "ami-7abd0209", > product code: https://aws.amazon.com/marketplace/pp/B00O7WM7QW), which is > supposed to have 4GB Memory in total, but turn out it is only "3.5GB". > A rough guess would be that the system has reserved some memory for crashkernel but that is a guess. I would look at /proc/commandline to see what the kernel is starting up with. -- Stephen J Smoogen.