You login to a Linux server with a performance issue: what do you check in the first minute?
uptime dmesg | tail vmstat 1 mpstat -P ALL 1 pidstat 1 iostat -xz 1 free -m sar -n DEV 1 sar -n TCP,ETCP 1 top
Rails LTS provides security patches for old versions of Ruby on Rails (2.3, 3.2, 4.2 and 5.2)