Itzikr's Blog

A guest post by Alan NG

Following on from part 1 , part 2, part 3 and part 4, we covered PowerFlex SDNAS System Features and took a deeper look (and walkthrough) of supported NAS protocols as well file system extension / shrinkage and security.

This post will cover the final key feature of PowerFlex that is data protection.

Note: We’ll be taking a deeper look and walkthrough at PowerFlex Data Protection for both Block and File in our next series.

Data Protection

As long as data is being created, there will always be a need to protect it as it is deemed valuable to any company. But how can this data be protected? There are various options available, either self-sufficient or through third-party software or hardware.

PowerFlex File offers customers two options for data protection: snapshots and 3-way NDMP backup (remote backup).

Snapshots

It is widely accepted that snapshots are a crucial data protection mechanism that every storage product must have. This is because they are considered one of the most basic features for data protection. There are many reasons why snapshots are popularly used, and all vendors offer snapshots as a standard feature but do note that snapshot is not a panacea for all situations and the following should be considered when creating snapshot :

• Snapshots are not full copies of the original data. Do not rely on snapshots for mirrors, disaster recovery, or high-availability tools. Because snapshots are partially derived from the real-time data of the file systems, they can become inaccessible if the storage resource becomes inaccessible.
• Although snapshots are space efficient, they consume overall system storage capacity. Ensure that the system has enough capacity to accommodate snapshots.
• When configuring snapshots, review the snapshot retention policy that is associated with the storage resource. You may want to change the retention policy in the associated rules or manually set a different retention policy, depending on the purpose of the snapshot.
• Manual snapshots that are created with PowerFlex Manager are retained for one week after creation (unless configured otherwise).
• If the maximum number of snapshots is reached, no more can be created. In this case, to enable creation of new snapshots,
  you are required to delete existing snapshots.

Creating a File Snapshot: Snapshots provide a way to create point-in-time copies of data, which can be used to recover data in the event of accidental deletion, data corruption, or other issues. Frequent snapshots offer multiple recovery points, allowing users to restore data to a specific point in time.

In this example, we create a snapshot rule every hour and keep for 24 hours.

There are 2 different access type for the file snapshot:

1. Protocol (Read Only) – The entire file system snapshot may be shared and mounted on a client like any other file system.
2. Snapshot – The files within the snapshot may be access directly from the production file system in the snapshot subdirectory of each directory.

Do take note that the timing used by the system for snapshot is based on UTC, hence, the backup administrator will have to customise the timing of the snapshot based on his timezone.

Creating a Policy: Taking snapshots manually can be a tedious task for backup admins, providing little job satisfaction. The good news is that PowerFlex has a built-in snapshot policy feature that eliminates the need for manual snapshots. Administrators can set up a policy with rules for snapshot frequency, retention period, read-only or secure snapshot, and other parameters, allowing the system to automatically handle snapshot tasks

• Time efficiency: Creating a snapshot is generally faster than making a full backup of data. This is because a snapshot only captures the changes made since the last snapshot, rather than copying all of the data.
• Cost efficiency: Snapshots can be less expensive than making full backups because they require less storage space and can be created more frequently. This can be especially useful for organizations with limited storage resources.
• Test and development: Snapshots can also be used to create test and development environments, allowing developers to work with a copy of the data without affecting the production system.
• Data analysis: Snapshots can be used for data analysis, allowing users to compare changes over time and identify trends or anomalies.

Assigning a protection policy to a file system: Assign a protection policy to a file system Assign a protection policy to one or more file systems to apply the snapshot rules included in the policy to the file systems. The protection policy automatically performs snapshot operations based on the specified parameters. If a protection policy that meets your data protection requirements is available, you can assign it to a file system at any time. You can assign protection policy to a file system during the resource creation or at a later stage.

Restore a file system from a snapshot. (Back to a point in time)

• You can use the restore operation to replace the contents of a file system storage resource with data from a snapshot that was taken directly from that storage resource. Restoring resets the data in that storage resource to the point in time at which the snapshot was taken. When restoring a file system, the source for the restore must be a snapshot that was taken directly from the storage resource that you are restoring.

Refresh a file system using snapshot. (Updating a Snapshot)

The content of the snapshot is replaced with the current content of the file system from which the snapshot was taken.

• You can create a duplicate of the production environment. NOTE: Because the refresh operation replaces the contents of a file system, it is recommended to take a snapshot of the file system before refreshing it.
• Creating a backup allows you to revert to a previous point in time. Note: Before refreshing a snapshot, it is mandatory to shut down the application and unmount the file system that is running on the production host, and then flush the host cache to prevent data corruption during the refresh operation.

3 way NDMP Backup

Three-way NDMP backup is also known as remote NDMP backup. It is a method for backing up data stored in a network-attached storage (NAS) environment to a remote backup server or device over a network. This method involves using NDMP to establish a communication channel between the NAS device and the remote backup server, allowing the backup data to be transmitted securely over the network.

NDMP remote backup offers numerous benefits, such as faster backup and recovery times, reduced network traffic, and the ability to centralize backup and recovery operations. However, it is important to ensure that appropriate security measures are in place to protect the backup data during transmission over the network.