--- title: "Data - Concept and best practices" description: "- Data relates to any type of file (binary, text, code, images, etc.) that you want to use with OVHcloud AI tools." url: https://docs.us.ovhcloud.com/en/public-cloud/ai-machine-learning/data-concepts-best-practices lang: en --- > For AI agents: the complete documentation index is available at https://docs.us.ovhcloud.com/en/llms.txt, the full documentation bundle is available at https://docs.us.ovhcloud.com/en/llms-full.txt. # Data - Concept and best practices ## Definition - **Data** relates to any type of file (binary, text, code, images, etc.) that you want to use with OVHcloud **AI tools**. - **Object Storage** is a scalable, resilient, and secure storage place accessible from anywhere through HTTPS APIs. It is a perfect place to store static files for the long term. - **Volumes** are filesystem storage units mounted and used inside **AI Training jobs** and **AI notebooks**.   ## Best practices **OVHcloud Object Storage** should be used to persist any data needed by **AI Training jobs** or **AI notebooks**. There are two ways to manage your data: - You can upload and download data from your local environment using the CLI (see [how to install ovhai CLI](https://docs.us.ovhcloud.com/en/public-cloud/ai-machine-learning/cli-install-client.md)). Next, find out how to [manage your data with the CLI](https://docs.us.ovhcloud.com/en/public-cloud/ai-machine-learning/cli-overview.md). - You can use the [OVHcloud Control Panel](https://manager.us.ovhcloud.com/); see [create data container](https://docs.us.ovhcloud.com/en/public-cloud/ai-machine-learning/compliance.md).   ## How it works **AI Training jobs** and **AI Notebooks** can read and write data from and to the **OVHcloud Object Storage**. Here is what is happening under the hood.   ### AI Training 1. Before the job starts, data is synchronized **from** the object storage **into** an underlying filesystem volume. This synchronization is done during the `INITIALIZING` phase. 2. When the job starts, the volume is attached to the desired directory. Data is then available inside the job as long as the `RUNNING` phase lasts. 3. After the job stops, data is synchronized back **from** the underlying filesystem volume **into** the **OVHcloud Object Storage**. This synchronization is done during the `FINALIZING` phase.   ### AI Notebooks 1. Before the notebook starts, data is synchronized **from** the object storage **into** an underlying filesystem volume. This synchronization is done during the `STARTING` phase. 2. When the notebook starts, the volume is attached to the desired directory. The data is then available within the job as long as the `RUNNING` phase lasts. 3. After the notebook stops, data is synchronized back **from** the underlying filesystem volume **into** the **OVHcloud Object Storage**. This synchronization is done during the `STOPPING` phase. This applies to your internal [/workspace](https://docs.us.ovhcloud.com/en/public-cloud/ai-machine-learning/ai-notebooks-workspace.md) and remote object storage volumes.   ## Capabilities ### Access rights Users can give three different access rights on **Filesystem volumes** attached to jobs and notebooks: **Read Only** (`RO`): You are only able to read data in your job or notebook. It is forbidden to write, modify, or delete data in this container. #### When to attach a volume in read-only RO... The purpose of **read-only** permissions is to ensure that you do not modify your data by mistake. This permission is recommended for your input data: images, videos, sounds, text, CSV files, etc. **Warning:** **NOTE:** Volumes that are in **read-only** mode are not synchronized with the Object Storage during the `FINALIZING` or `STOPPING` phase because there is no point in synchronizing data that has not changed during the life of a job or notebook. **Note:** If you have directly added data from the Object Storage to the container connected in `RO`, you can request an **intermediate synchronization**. Otherwise, your data will be **synchronized at the start of your next** job or notebook. **Read Write** (`RW`): You have full access to your data in your job or notebook. You can write, modify, or add data in this container. #### When to attach a volume in read-write RW... The purpose of the **read-write** permission is to modify the contents of the object container. This permission is recommended if your container contains code (e.g., a Python file), a notebook, or if you want to save a model or connection weights after your training. **Note:** Volumes that are in **read-write** do not allow you to **delete** data from your Object Storage. If you delete data from a job or notebook, it will still be present in your object container, even after synchronization. **Read Write Delete** (`RWD`): You have full access to your data in your job or notebook. You can write, modify, add, or **delete** data in this container. #### When to attach a volume in read-write-delete RWD... The purpose of the **read-write-delete** permission is to be able to modify or delete the object container contents. You can not only make changes to the different files in your container (Python code, requirements file, etc.) but also, especially, delete data from it. The RWD will allow you to permanently delete data you no longer need from your object container. This permission can be used if you want to delete old codes or connection weights, which can be heavy files. **Warning:** **NOTE:** After the synchronization phase, your data deleted from your notebook or job will be permanently deleted in the Object Storage. **Note:** For a volume in `RW` or `RWD`: As long as your job or notebook is in the `FINALIZING` or `STOPPING` state, this means that the upload is still in progress. Once the state changes to `INTERRUPTED` or `STOPPED`, it means all the data was uploaded to your Object Storage.   ### Volume caching and sharing By default, **filesystem volumes** are created and deleted on the fly for each job as needed. Users can enable a `cache` feature that allows jobs and notebooks to reuse available volumes instead of creating a new one each time. That feature serves two purposes: - Reducing synchronization time for data that has already been downloaded before. - Sharing the same volumes between several jobs or notebooks. **Warning:** **NOTE:** Unused volume data is deleted after three days. Users should not rely on this `cache` feature for long-term persistence.   ## Go further Browse all the [AI & Machine Learning guides](https://docs.us.ovhcloud.com/en/public-cloud/ai-machine-learning/landing-page-ai-machine-learning.md). Browse the rest of the [OVHcloud US documentation](https://docs.us.ovhcloud.com/en/index.md) for guides on our other products and services. Learn more about [AI & Machine Learning](https://us.ovhcloud.com/public-cloud/ai-machine-learning/) on the OVHcloud US website. If you need training or technical assistance to implement our solutions, contact your sales representative or click on [this link](https://us.ovhcloud.com/professional-services/) to get a quote and ask our Professional Services experts for a custom analysis of your project.