To transition into a system administrator role from technical support, begin by deeply understanding the systems you'll manage, including servers, networks, and operating systems. Obtain relevant certifications like CompTIA Network+ or MCSA/MCSE. Gain practical experience through labs or volunteering for system-related tasks. Develop expertise in scripting and automation, such as PowerShell or Bash. Hone your troubleshooting and problem-solving abilities.
If you are interested in getting into this field, then check out this video about Mohammed Riyaz and how he got promoted with a good salary hike just after completing Intellipaat's Advanced Certification in Cloud Computing.