It is an international day of backups. A good one can save a person from a headache after accidental deletion of some important files. It can also save millions of dollars for a company that got hit by a ransomware attack and got its disks encrypted. It should be stored appropriately and validated by performing a test of restoring the data from time to time. It may take some time to set up the backup system — but it is far better to spend that time setting things up correctly than to have to deal with a disaster of a major data loss without a reliable solution. Since everyone is (or eventually will be) periodically backing up all of the important data, I will briefly describe some of the options for keeping your important digital information safe from loss in Azure.
Redundancy of storage
Before proceeding with the solutions, it is worth mentioning the types of redundancy. There are basically three of those:
- LRS — Locally-redundant storage
- ZRS — Zone-redundant storage
- GRS — Geo-redundant storage
LRS means that we keep the backup in the same datacenter that the source resides in. It is not recommended for crucial data.
ZRS replicates the data across one or more availability zones (datacenters in the same region). Big portion of Azure regions have 3 availability zones, but it is not always the case.
GRS is the most resilient option. It copies the information across one or more regions.
Recovery Services Vaults
One of the most popular services on Azure are Virtual Machines, and one way to back them up is via Recovery Services Vaults.
They Can be used for backing up:
- Virtual machines
- Azure file shares
- SQL servers in Azure VM
- SAP HANA in Azure VM
By default, Recovery Service Vaults set storage replication to GRS, but this can be altered. The default policy is to backup daily at 6:00 PM UTC, keep instant recovery snapshots for 2 days and to retain every backup for 30 days. The data is encrypted by platform-managed keys, but you can choose to encrypt your data using encryption keys owned and managed by you. Azure Backup lets you use your RSA keys stored in the Azure Key Vault for encrypting your backups.
You can even back up your on-premise VMs or certain files and folders with an aid of Microsoft Azure Backup Server or Recovery Services agent.
The cost of using this service depends on the number of protected instances and the storage space used. The first backup is a full one, and the following are incremental.
For a one machine under 50GB we would pay around 9$ per month for a GRS backup.
Backup and Restore feature for App Service
You can easily backup:
- File content
of your App Service hosted on a Standard (or above) App Service Plan.
The backup will be located in a given storage container of a given storage account. You can set your storage account to be LRS, ZRS, or GRS.
The cost depends on the storage that these files will occupy. If our app with the database would use 10GB, then we would pay around 0.35€ for storing one full backup for a month