I installed the log4j patch for ArcGIS Server and DataStore and it only took about 5 minutes.
Now I'm installing the log4j patch for Portal on a different Windows server and its been running for about 45 minutes. Could this be due to too few resources on the Windows Server as my org reduced the CPU to 2 processors and RAM to 8 GB?
What version of ArcGIS are you using? ArcGIS 10.8.1 and earlier were notoriously slow for any patches to apply, often in the 40-70 minute bracket (per patch). 10.9.1 is much faster.