Whitepaper - Disaster Recovery with StepWise
Copyright Invizion Pty Ltd. All rights reserved. First Published October, 2010 Invizion believes the information in this publication is accurate as of its publication date. The information is subject to change without notice. THE INFORMATION IN THIS PUBLICATION IS PROVIDED AS IS. INVIZION PTY LTD MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WITH RESPECT TO THE INFORMATION IN THIS PUBLICATION, AND SPECIFICALLY DISCLAIMS IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Use, copying, and distribution of any Invizion software described in this publication requires an applicable software license. Invizion Pty Ltd products are the exclusive trademarks of Invizion Pty Ltd. All other trademarks used herein are the property of their respective owners. Invizion Pty Limited Whitepaper - Stepwise Disaster Recovery Planning 2
Table of Contents About this Whitepaper... 4 Executive Summary... 4 Audience... 4 Introduction... 5 Backup and Restore Considerations... 6 Backup Sychronisation... 6 Restore Synchronisation... 7 Logical Storage Device Structure... 8 Single tier storage on single physical device... 8 Multi-tier storage, single physical device storage... 8 Multi-tier storage, multiple physical device storage... 9 Invizion Pty Limited Whitepaper - Stepwise Disaster Recovery Planning 3
About this Whitepaper This whitepaper provides planning and guidance on disaster recovery when implementing Stepwise Enterprise Storage System as a Remote Blob Storage solution. Executive Summary Stepwise Enterprise Storage System uses the Microsoft Remote Blob Storage technology to externalise Binary Large Objects (BLOBs) from a Microsoft SQL Server database to a local or remotely hosted filesystem. This process changes the backup and restore methodology required to successful perform recover from a system failure. This document addresses some of these challenges as well as providing guidance on the additional recovery options that are available when using Stepwise for Remote Blob Storage. Audience This paper is intended for IT Professionals. Invizion Pty Limited Whitepaper - Stepwise Disaster Recovery Planning 4
Introduction Deploying Stepwise for Remote Blob Storage can successfully reduce a content database s size by up to 95%. This drastically reduces the size of the Microsoft SQL Server database and greatly reduces the time required to successfully backup and restore a database as the result of a system failure. However, this does add an additional data source to consider the file-based system that Stepwise uses to store BLOB data also needs to be backed up and managed. There are a number of considerations that must be taken into account when designing a backup system, most of which are beyond the scope of this document. These include: Dedicated backup network connections Switch/network design for increased throughput Network configuration (such as Jumbo packet settings) Offsite replication Disk vs tape vs dedicated backup hardware Some of these concepts will be touched on in this whitepaper, however Enterprise architects should consider engaging a backup design expert to ensure the backup system is adequate. Invizion Pty Limited Whitepaper - Stepwise Disaster Recovery Planning 5
Backup and Restore Considerations Remote Blob Storage adds an additional element to the standard SharePoint backup environment the physical devices where the BLOBs are stored. Because of this, backup engineers need to design their backups to be synchronised across the environment. Backup Sychronisation When SharePoint stores a new document, or creates a new version of a document, it adds the metadata and document to the content database. When Stepwise is enabled against a content database, only the metadata is stored in the content database the document is stored in the Stepwise storage system. This presents a moving target to backup synchronisation. The primary point of connection between SharePoint and Stepwise is the content database, so this should always be backed up prior to backing up the Stepwise physical storage system. This is because when a restore is required, the content database will hold the point-in-time information about all documents loaded into SharePoint, and the file system restore will hold all the associated documents as well as any documents that were added in between when the database backup was completed and the file system backup is completed. Figure 1 Backup Synchronisation Schedule This synchronisation will ensure that BLOBs either match or exceed the items that are referenced by SharePoint. Different physical environments may require different backup schedules, particularly if multiple storage tiers are used. For example, it is common to split storage tiers into data that has been created (for example) in the last 30 days, and anything older than 30 days is moved to a different storage tier. Backup schedules than then be accommodated to fit in with this: Storage Tier Purpose Backup Schedule Store most recent 30-days worth of BLOBs Incremental backup nightly, full backup weekly Store BLOBs 30+days Incremental backup weekly, full backup monthly (1) (1) Even though this schedule overlaps with the first, it allows Backup Administrators flexibility to restore a single storage tier Invizion Pty Limited Whitepaper - Stepwise Disaster Recovery Planning 6
Restore Synchronisation Restore synchronisation depends on the design of your Stepwise implementation, and the circumstances that require a restore. In a scenario where there has been actual loss of services (such as SQL Server, content database, or a physical storage device that Stepwise uses) the following scenarios may apply. If you are restoring due to Loss of content database (such as database corruption, hardware failure, etc) Loss of filesystem (such as filesystem corruption, failed hard drives, hardware failure, etc) Complete loss of both databases and filesystem then your restore process is Only restore the content database. The existing Stepwise storage system is unaffected and BLOBs will already be available on the system NOTE: you may have lost references to documents in Stepwise inbetween the last database backup. Stepwise can identify what BLOBs were created during this time period. Only restore the filesystem for Stepwise. The existing content database is unaffected NOTE: you may have lost some BLOBs inbetween the last file-based backup. Stepwise can identify what BLOBs are missing by comparison to the SharePoint content database(s) Restore the content database first then restore the filesystem for Stepwise. This will enable users to start using SharePoint again for creation of new documents with Stepwise, and previous documents will be restored as per your restore window. Invizion Pty Limited Whitepaper - Stepwise Disaster Recovery Planning 7
Logical Storage Device Structure The physical devices available to Stepwise can be further sliced into logical areas for effective BLOB storage. The simplest example is an NTFS file share that has separate folders created for each SharePoint content database. By managing the Stepwise storage devices, backup and restore operations can be targeted dependant on backup schedule, retention schedule, and/or Service Level Agreement requirements. Single tier storage on single physical device This storage design stores all BLOBs on a single physical device, such as a network share on a file server or SAN device. In this example, only a single Stepwise storage device is configured Stepwise and documents are not moved to other locations. Figure 2 Single-tier storage system This configuration is usually relevant in a small environment such as a test or proof-of-concept configuration. In this scenario a backup/restore operation would need to only target the one filesystem component. Multi-tier storage, single physical device storage This storage design stores all BLOBs on a single physical device. Documents are moved between Stepwise storage devices based on storage policies created within Stepwise. Figure 3 Single-tier physical system with multiple Stepwise storage devices Invizion Pty Limited Whitepaper - Stepwise Disaster Recovery Planning 8
In this scenario a backup design could include separate backup policies based on the storage policies of Stepwise, or the entire physical device could be backed up using a fibre-switch network or similar high-performing backup method. Multi-tier storage, multiple physical device storage This storage design stores BLOBs across multiple physical storage devices, which could include network shares, storage devices, or cloud-based storage systems. Documents are moved between storage devices based on storage policies created within Stepwise, which may entail movement between physical devices or on the same physical device, dependant on Stepwise configuration. Figure 4 Multi-tier physical system with multiple Stepwise storage devices This is a more complex storage architecture design and would require multiple backup methodologies. However it provides the most flexibility and can allow for a more advanced, distributed architecture that takes into account geographical locations, secondary sites, etc. Invizion Pty Limited Whitepaper - Stepwise Disaster Recovery Planning 9