I am planning to upgrade from 1.9.4 to latest 1.19.X LTS. please let me know if i can directly upgrade it to 1.19.x or there will be step migration.
we are on cent7 and want to migrate vault to rocky9.7.
Vault is HA cluster using Consul as shared storage
consul cluster is 3‑node Consul server + client agents architecture
Quick answer : No.
Longer answer: You have quite a few changes here, you may want to spend some planning time to review all the changes both at OS level and Vault level ( PKI had a big transition at vault 1.11 ), and if you stay with Consul, they have changes as well.
Doing all of this in one step will have significant risk.