I have asked one of my hostings to update the version of PHP and MySQL and they have replied telling me to be sure I have a backup of my databases as well as of the content of the page because during the update some data can be lost.
Is this just a way to cover their back in case of any incompetent doing bad their job? Or can it really result in a potential lose of data for some reason?
I am not really on the mod of downloading all the site, which is quite big and with thousands of images, and I was wondering which are the probabilities of suffering lose of data in this operation.
Thanks.