Google offers several data storage services to choose from. Let me start by giving you a high-level overview of these different services.

Cloud Storage is an object storage service

Cloud Storage is Google Cloud’s object storage service, and it allows worldwide storage and retrieval of any amount of data at any time. You can use Cloud Storage for a range of scenarios including serving website content, storing data for archival and disaster recovery, or distributing large data objects to users via direct download.

Cloud Storage key features

• It’s scalable to exabytes of data
• The time to first byte is in milliseconds
• It has very high availability across all storage classes
• And It has a single API across those storage classes

Cloud Storage has four storage classes: Standard, Nearline, Coldline, and Archive and each of those storage classes provides 3 location types:

• Multi-region is a large geographic area, such as the United States, that contains two or more geographic places.
• Dual-region is a specific pair of regions, such as Finland and the Netherlands.
• A region is a specific geographic place, such as London.

Objects stored in a multi-region or dual-region are geo-redundant

Cloud Storage is broken down into a couple of different items here.

• First of all, there are buckets that are required to have a globally unique name and cannot be nested.
• The data that you put into those buckets are objects that inherit the storage class of the bucket and those objects could be text files, doc files, video files, etc.
• There is no minimum size to those objects and you can scale this as much as you want as long as your quota allows it.
• To access the data, you can use the gsutil command, or either the JSON or XML APIs.

When you upload an object to a bucket, the object is assigned the bucket’s storage class, unless you specify a storage class for the object. You can change the default storage class of a bucket but you can’t change the location type from regional to multi-region/dual-region or vice versa. You can also change the storage class of an object that already exists in your bucket without moving the object to a different bucket or changing the URL to the object.

Setting a per-object storage class is useful, for example, if you have objects in your bucket that you want to keep, but that you don’t expect to access frequently. In this case, you can minimize costs by changing the storage class of those specific objects to Nearline, Coldline, or Archive Storage.

There are also several features that come with Cloud Storage.

• Customer-supplied encryption keys when attaching persistent disks to virtual machines. This allows you to supply your own encryption keys instead of the Google-managed keys, which is also available for Cloud Storage.
• Object Lifecycle Management which lets you automatically delete or archive objects.
• Object versioning allows you to maintain multiple versions of objects in your bucket. You are charged for the versions as if they were multiple files, which is something to keep in mind.
• Directory synchronization so that you can sync a VM directory with a bucket.
• Object change notifications can be configured for Cloud Storage using Pub/Sub. We will discuss this later.

Let’s look at access control for your objects and buckets that are part of a project.

• We can use IAM for the project to control which individual user or service account can see the bucket, list the objects in the bucket, view the names of the objects in the bucket, or create new buckets. For most purposes, IAM is sufficient, and roles are inherited from project to bucket to object.
• Access control lists or ACLs offer finer control.
• For even more detailed control, signed URLs provide a cryptographic key that gives time-limited access to a bucket or object.
• Finally, a signed policy document further refines the control by determining what kind of file can be uploaded by someone with a signed URL

Thank you for taking the time to read my article on Google cloud Object storage service, stay tuned as I explore other storage services offered by Google cloud.