@Michael BronsonIt depends on whether the compoennts are going to use the new disks or not. If not, they don't need to restart. For those services that need to use the new disk. Some of them, such as HDFS datanode supported Hot-Swap, which means you can add disks by the following steps without a restart of datanode service.
1> changing the dfs.datanode.data.dir from hdfs-site.xml to include new disk locations (e.g., /data/disk2).
<property>
<name>dfs.datanode.data.dir</name>
<value>/data/disk1,/data/disk2</value>
</property>
2> Run hdfs CLI to reconfig datanode service without a restart.
hdfs dfsadmin-reconfig datanode dn1.hdp.com:9820 start
Other services might need a restart to use the new disks if Hot-Swap is not supported.