redis redis-trib.rb  에러 발생시

redis 실행 해보니 아래 메세지가 발생시 패키치를 더 설치해줬다.
$ ./redis-trib.rb
/usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require’: cannot load such file — redis (LoadError)
from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require’
from ./redis-trib.rb:25:in `<main>’
$ yum install ruby ruby-devel rubygems rpm-build
$ gem install redis