Hello Prince ,

Looks like you are trying to upgrade the Virtual DC.

Whenever you are performing the upgrade , the release notes is an helpful factor. Here is the release notes for 5.3.1.

• FireSIGHT System Release Notes, Version 5.3.1

http://www.cisco.com/c/en/us/td/docs/security/firesight/531/relnotes/FireSIGHT-System-Release-Notes-Version-5-3-1.html

It will give you an approximate time factor and also give you a good idea about the pre-requisites and requirements.  But still its all depends on the resources and the mysql database in the VDC. If you  have a decent enough amount of mysql connection data stored in the device , then this may take more time. It always better to perform the upgrades in  off- business hours . Even if the VDC wont cause any traffic interruption , its better to perform the upgrades in the change window.

Even if the upgrade gets stuck on any specific script for sometime, don't abort the upgrade in between. Its expected that for some database and file  check integrity scripts and sru check scripts , the upgrade script will take  more time.Hence please don't try to abort the upgrade in between since this will break the mysql tables. Let the upgrade run and don't interrupt the upgrade even if it takes more time to finish. Until or unless it fails, you are not supposed to kill or manually interrupt the upgrade.

Rate if my answer helps you.

Regards

Jetsy