Dropbox recently updated their glibc requirement to version 2.19. Centos 7 has version 2.17. It seems not to be a good idea to replace glibc manually. Is there any other workaround?
According to Dropbox, only Fedora 21+ and Ubuntu 14.04+ are supported as they are delivered with the required versions of
glibc and supported filesystems.
You should not be replacing
glibc on a system unless you really know what you are doing. You could keep the default
glibc and compile or install a newer version in a non conflicting location, then compile Dropbox against that and try to get it working.
You could try using Docker to run Dropbox, there are apparently a few people that have had that idea but I have no direct experience with using Dropbox that way.