On your OCI instance, you have a few different options for storage, depending on your need

Option 1: I don't need a ton of storage

Every OCI instance comes with what is called a boot volume, which is essentially a predefined amount of storage that does not scale up or down. This storage option is fairly cheap, and supports up to 32TB of storage. 

Other storage options are considerable more expensive (~10x). We very highly recommend you choose this options. Furthermore, depending on your performance requirements for storage, Oracle allows tuning of disk speed.

If your job is mostly compute-heavy and does not require or store a lot of data, you are probably fine with just using the home directory at /home/opc. Most nodes have at least 32GB Storage on this partition, that is being paid for no matter what.

Option 2: I need a metric boatload of storage AND i need fast filesystem access to it like it was just another drive.

An OCI SLURM stack has a directory at /app that both scales infinitely and makes sure you only pay for what you use.

This is the recommended way to store your data, and is best for most use cases

Option 3: I need a metric boatload of storage BUT i don't need to access it very often.

Oracle has an option to create what are called buckets.

Depending on how you need to use the data and how much you need to store, using this option can lead to considerable savings, though at a price to operativity.

Getting data in and out of the buckets takes time and possibly costs a retrival fee, and needs to be done via commands and api's unlike the /app folder that automatically handles everything for you.

Unless you know you need to store hundreds of terabytes in a cold-storage like environment, we do not recommend this option. To see more about Object Storage on Oracle, see the following link https://docs.oracle.com/en-us/iaas/Content/Object/Concepts/understandingstoragetiers.htm