If the initial storage period isn't sufficient, you do have the option to extend it. You can specify the maximum number of epochs when uploading, which is up to 53 epochs (approximately 2 years). Additionally, there's an extension function that allows you to extend the storage period later if needed.

The data in Walrus is initially stored for as many epochs as you specify during the upload. For instance, in the mainnet, 1 epoch equals 14 days.