Although part of the Spectrum upgrade installation process for Spatial is to automatically back up the data from a previous release before the upgrade continues, it is important to back up custom data sources and resources prior to upgrading using the limrepo export command in the Administration Utility (see the Administration section of the Spectrum Spatial Guide for instructions).
Any data that was installed with the module will be deleted after upgrade. If custom data is located in the same directories, back it up and copy to the same location in the Spectrum Technology Platform directories once upgraded. Pay special attention to any data or resources that have been added to default locations within the SpectrumDirectory/server/modules/spatial/ directory, as these will be deleted after upgrade. For example, if you have used the default TileCache directory for generating your map tiles, back it up, and copy to the same location once upgraded.
It is also very important to perform a backup of the repository after the Spectrum Technology Platform upgrade is successful, to serve as a baseline in case your repository becomes corrupt later on.