diff --git a/attributes/repo.rb b/attributes/repo.rb
index b58fb12..6089a8c 100644
--- a/attributes/repo.rb
+++ b/attributes/repo.rb
@@ -35,9 +35,9 @@ when "fedora"
 when "suse"
   # (Open)SuSE default repositories
   # Chef doesn't make a difference between suse and opensuse
-  suse = %x[ head -n1 /etc/SuSE-release| awk '{print $1}' ].chomp.downcase # can be suse or opensuse
+  suse = Mixlib::ShellOut.new("head -n1 /etc/SuSE-release| awk '{print $1}'").run_command.stdout.chomp.downcase
   suse = "sles" if suse == "suse"
-  suse_version = suse << %x[ grep VERSION /etc/SuSE-release | awk -F'= ' '{print $2}' ].chomp
+  suse_version = suse << Mixlib::ShellOut.new("grep VERSION /etc/SuSE-release | awk -F'= ' '{print $2}'").run_command.stdout.chomp
 
   default['ceph']['suse']['stable']['repository'] = "#{node['ceph']['repo_url']}/rpm-#{node['ceph']['version']}/#{suse_version}/x86_64/ceph-release-1-0.#{suse_version}.noarch.rpm"
   default['ceph']['suse']['testing']['repository'] = "#{node['ceph']['repo_url']}/rpm-testing/#{suse_version}/x86_64/ceph-release-1-0.#{suse_version}.noarch.rpm"
diff --git a/recipes/mds.rb b/recipes/mds.rb
index 9546dfd..73f9034 100644
--- a/recipes/mds.rb
+++ b/recipes/mds.rb
@@ -32,7 +32,9 @@ end
 
 ruby_block "create mds client key" do
   block do
-    keyring = %x[ ceph auth get-or-create mds.#{node['hostname']} osd 'allow *' mon 'allow rwx' --name mon. --key='#{node["ceph"]["monitor-secret"]}' ]
+    cmd = "ceph auth get-or-create mds.#{node['hostname']} osd 'allow *' mon 'allow rwx' --name mon. --key='#{node["ceph"]["monitor-secret"]}'"
+    keyring = Mixlib::ShellOut.new(cmd).run_command.stdout
+
     keyfile = File.new("/var/lib/ceph/mds/#{cluster}-#{node['hostname']}/keyring", "w")
     keyfile.puts(keyring)
     keyfile.close
diff --git a/recipes/osd.rb b/recipes/osd.rb
index 1d82923..6665542 100644
--- a/recipes/osd.rb
+++ b/recipes/osd.rb
@@ -40,7 +40,7 @@ end
 
 package 'cryptsetup' do
   action :upgrade
-  only_if { node[:dmcrypt] }
+  only_if { node['dmcrypt'] }
 end
 
 service_type = node["ceph"]["osd"]["init_style"]
@@ -72,33 +72,24 @@ else
   end
 
   if crowbar?
-    ruby_block "select new disks for ceph osd" do
-      block do
-        do_trigger = false
-        node["crowbar"]["disks"].each do |disk, data|
-          if node["crowbar"]["disks"][disk]["usage"] == "Storage"
-            puts "Disk: #{disk} should be used for ceph"
-
-            system 'ceph-disk-prepare', \
-              "/dev/#{disk}"
-            fail 'ceph-disk-prepare failed' unless $?.exitstatus == 0
-
-            do_trigger = true
-
-            node.set["crowbar"]["disks"][disk]["usage"] = "ceph-osd"
-            node.save
-          end
-        end
-
-        if do_trigger
-          system 'udevadm', \
-            "trigger", \
-            "--subsystem-match=block", \
-            "--action=add"
-          fail 'udevadm trigger failed' unless $?.exitstatus == 0
-        end
-
+    node["crowbar"]["disks"].each do |disk, data|
+      execute "ceph-disk-prepare #{disk}" do
+        command "ceph-disk-prepare /dev/#{disk}"
+        only_if { node["crowbar"]["disks"][disk]["usage"] == "Storage" }
+        notifies :run, "execute[udev trigger]", :immediately
       end
+
+      ruby_block "set disk usage for #{disk}" do
+        block do
+          node.set["crowbar"]["disks"][disk]["usage"] = "ceph-osd"
+          node.save
+        end
+      end
+    end
+
+    execute "udev trigger" do
+      command "udevadm trigger --subsystem-match=block --action=add"
+      action :nothing
     end
   else
     # Calling ceph-disk-prepare is sufficient for deploying an OSD