Update ruby with rvm

hello.
hope someone can help me in this great forum.
i’m newbie in ruby word.
i have a server ( debian 7 ) with ruby 1.9.3-p194 (2012-04-20)
[i486-linux] .
i woud like to update ruby version to 2.2.6 ( to update redmine ) .
i some forum, i found a solution : install rvm.
so i did:

rvm info

ruby-2.2.6:

system:
uname: “Linux yamazaki 3.2.0-4-686-pae #1 SMP Debian
3.2.73-2+deb7u3 i
686 GNU/Linux”
system: “debian/7/i386”
bash: “/bin/bash => GNU bash, version 4.2.37(1)-release
(i486-pc-linu
x-gnu)”
zsh: " => not installed"

rvm:
version: “rvm 1.28.0 (latest) by Wayne E. Seguin
<[email protected]
m>, Michal P. [email protected] [https://rvm.io/]”
updated: “17 hours 35 minutes 18 seconds ago”
path: “/usr/local/rvm”

ruby:
interpreter: “ruby”
version: “2.2.6p396”
date: “2016-11-15”
platform: “i686-linux”
patchlevel: “2016-11-15 revision 56800”
full_version: “ruby 2.2.6p396 (2016-11-15 revision 56800)
[i686-linux]”

homes:
gem: “/usr/local/rvm/gems/ruby-2.2.6”
ruby: “/usr/local/rvm/rubies/ruby-2.2.6”

binaries:
ruby: “/usr/local/rvm/rubies/ruby-2.2.6/bin/ruby”
irb: “/usr/local/rvm/rubies/ruby-2.2.6/bin/irb”
gem: “/usr/local/rvm/rubies/ruby-2.2.6/bin/gem”
rake: “/usr/local/rvm/rubies/ruby-2.2.6/bin/rake”

environment:
PATH:
“/usr/local/rvm/gems/ruby-2.2.6/bin:/usr/local/rvm/gems/ruby-2
.2.6@global/bin:/usr/local/rvm/rubies/ruby-2.2.6/bin:/usr/local/sbin:/usr/local/
bin:/usr/sbin:/usr/bin:/sbin:/bin:/root/.rvm/bin”
GEM_HOME: “/usr/local/rvm/gems/ruby-2.2.6”
GEM_PATH:
“/usr/local/rvm/gems/ruby-2.2.6:/usr/local/rvm/gems/ruby-2.2.6
@global
MY_RUBY_HOME: “/usr/local/rvm/rubies/ruby-2.2.6”
IRBRC: “/usr/local/rvm/rubies/ruby-2.2.6/.irbrc”
RUBYOPT: “”
gemset: “”


ruby -v
ruby 2.2.6p396 (2016-11-15 revision 56800) [i686-linux]

i have to use passenger for apache. so when i do:
passenger-install-apache2-module
i have this error:

Unable to autodetect the currently active RVM gem set name. This could
happen if you ran this program using ‘sudo’ instead of ‘rvmsudo’. When
using RVM, you’re always supposed to use ‘rvmsudo’ instead of ‘sudo!’.

Please try rerunning this program using ‘rvmsudo’. If that doesn’t help,
please contact this program’s author for support.

with rvmsudo:
rvmsudo passenger-install-apache2-module
-bash: rvmsudo: command not found

i would like to know how to install properly ruby 2.2.6 with root user
through ssh ( i’m using putty ) .
thanks.