Update howto-upgrade-nexus-fabric.md

Author: sushantjrao

articles/operator-nexus/howto-upgrade-nexus-fabric.md

@@ -27,8 +27,10 @@ Runtime changes are categorized as follows:
 
 ### **Prerequisites**
 
-Confirm that the Network Fabric Controller is in a 'Provisioned' state.
+- Confirm that the Network Fabric Controller is in a 'Provisioned' state.
 
+- Make sure that all the Network Fabric devices are in healthy state before proceeding with major runtime version upgrade.  
+ 
 ### **Upgrade workflow**
 
 #### **Step 1: Verify Fabric runtime version**
@@ -83,7 +85,7 @@ Follow the recommended sequence for device upgrades, addressing any failures man
 
 - Verify all devices are configured and synchronized.
 
-- Ensure that there is at least **3GB of available disk space** within the directory `/mnt` to proceed with NNF device upgrade .
+- Ensure that there is at least **3.5GB of available disk space** within the directory `/mnt` to proceed with NNF device upgrade .
 
 Upgrade individual devices with the following command:
 
@@ -135,5 +137,5 @@ Check the version status of all devices and the fabric with AZCLI commands.
 ### **Known issues**
 
 1. Create the EOS image directory manually at `/mnt/nvram/nexus/eosimages` if it is missing. This is especially important for environments built from older NF versions.
-2. NNF device upgrades fail when the available disk space within the directory `/mnt` is less than 3GB. Perform a manual clean up to free up disk space within the NNF device and then retry the upgrade operation.
+2. NNF device upgrades fail when the available disk space within the directory `/mnt` is less than 3.5GB. Perform a manual clean up to free up disk space within the NNF device and then retry the upgrade operation.