Challenges and Options for Filesystem Backups at Petabyte Scale

The data growth for unstructured data is accelerating and filesystems that contain one or multiple petabyte are common. The current version of OneFS 7.1 has a tested support for 20PB of raw capacity, new node types and larger disks will lift that limit going forward. Challenges start even before a filesystem size reaches a petabyte. In this post I will identify the challenges that come along with such large filesystems. Even though the Isilon data protection mechanisms are very mature [1] you may want to backup your data to prevent logical or physical data due to disasters or for compliance reasons. We’ll define what the attributes of an ideal backup solution are and compare some existing technical solutions against this list of attributes and functions. The list of technical solutions is determined by my working experience and discussion with some renown colleagues from EMC’s Data Protection Availability Division (see Acknowledgement) and I would not make a claim for completeness.

 

The challenges

 

The NDMP challenge

Remember that the context of this discussion is LARGE filesystems. The industry standard solution for backing up NAS appliances is the NDMP protocol. I have mentioned several disadvantages of NDMP in a recent post. By far the biggest challenge is that NDMP does not support a progressive incremental forever strategy (well, there is an exception that I will explain later but without any 3rd party tools the statement is true). That means you need to perform a full backup every so often. In practice this is not feasible: assume we would have a dedicated 10 Gigabit Ethernet available for backup and we could saturate it with 900 MB/s. A full petabyte backup would still take

Use Isilon's new change-list feature to accelerate your backups

The new OneFS Changelist API

As mentioned in a previous post, OneFS can be completely managed through an API [1]. That's an important integration feature for environments like VMWare or interaction with other solutions.In this post is about the changelist API that it typically used by backup software to manage OneFS snaphots. Networker 8.2 and other backup software solutions for example use this API to manage and control snapshots. As we go forward we can expect that more and more data management solutions will make use of the API. However, you can also make use of the new changelist function (through API or CLI) to create a list of files that lists files which have been changed between two snapshots. If you backup software does not yet use the API itself, you can use the list and feed it into your backup client for faster backups.

This is not about NDMP

Although the new OneFS Version 7.1.1 has some new and cool NDMP features like snapshot based backup and parallel restore (see more in the OneFS 7.1.1 Release Notes [1]), many people favor to avoid NDMP at all. Here are some reasons:

Isilon as a TSM Backup Target – Analyses of a Real Deployment

In my recent blog “Using Isilon as a Backup Target” I have explained why Isilon is a perfect target for TSM backups (well, the same applies for sure to other backup and archive solutions as well but we want to show real world example here and this one has been with TSM). Beside the nice and simple administration and the fact that you can get rid of the SAN complexity for a large degree, one of the most appealing advantages is that your whole backup process becomes much faster. Why? Because

Isilon vs. SONAS Part 6: Remote Replication

SONAS vs. Isilon Part 6: Remote Replication

In this article we’ll look at the remote replication implementations of both systems. The comparison is based on SONAS 1.4 and Isilon OneFS 7.0. Both systems provide asynchronous replication with configurable RPOs.

Use Cases

Asynchronous replication is typically used for large scale filesystems for the following use cases:

• Disaster Recovery
• Business continuance
• Disk-to-Disk backup
• Remote disk archive

Although a zero RPO cannot be achieved using asynchronous replication, it is typically feasible for non-