Release Notes > Upgrade Path > Before Upgrade - Important!
Before Upgrade - Important!
1. Before performing an upgrade, back up your current configuration.
2. To ensure a successful upgrade, run the Upgrade Advisor Tool with your current configuration and the target version. Then, perform the required actions as instructed in the report output. The Upgrade Advisory Tool includes all the limitation and upgrade considerations specifically relevant to the source configuration, version, device details, and target version. Make sure to update the Upgrade Advisory Tool DB before performing the analysis. The Upgrade Advisor Tool is available on the Customer Portal.
3. Read the Upgrade Limitations below:
Upgrade Limitations
Item
Description
Bug ID
1.  
When upgrading from version 30.5.2.x or earlier to newer versions, you first must upgrade to version 30.5.3.0, and then to the later versions.
prod00268917
2.  
Starting with version 31.0, Alteon 5224 VX with 24 GB RAM supports 16 vADCs (compared to 20 vADCs in earlier versions).
DE21457
3.  
Installing the image fails when upgrading from versions earlier than 29.0.9.0 to versions 30.2.7.0 and later.
Workaround: Use an intermediate version such as 29.0.9.0 or a later 29.0.x version. For example: 29.0.3.0 > 29.0.9.0 > 30.2.7.0.
 
4.  
Installing the image fails when upgrading from versions earlier than 29.5.8.0 to versions 30.2.7.0 and later.
Workaround: Use an intermediate version such as 29.5.8.0 or a later 29.5.x version. For example: 29.5.4.0 > 29.5.8.0 > 30.2.7.0.
 
5.  
After upgrading from version 30.5.3.0 to 31.0 with syslog servers configured, the configuration remains in diff.
Reason: The syslog settings in version 30.5.3 contain the syslog port, while the syslog settings in version 31.0 do not support it.
Workaround: Before the upgrade, remove the syslog settings from the configuration. After upgrade, reconfigure the syslog settings.
DE22603
6.  
After upgrade to version 31.0 with a duplicate syslog server IP address configured, the configuration remains in diff and the following error displays:
Duplicate Syslog Server with same IP <syslog IP>
Workaround: Remove the duplicated syslog setting from the configuration before the upgrade.
DE21305