Every email archiving tool emphasizes a different feature or capability. Some email archiving vendors tout scalability; others underscore data reduction features, search performance, storage integration or security. Some email archiving products are appliances that include software and storage. Others are software tools that provide management, migration and security features, but rely on integration with storage hardware or other software products to provide full functionality.
SearchStorage.com has already covered the general issues involved in purchasing archiving products. Below you'll find a list of the features you'll want to evaluate when purchasing an email archiving product.
Criteria for evaluating email archiving products
Email data movement. Email messages cannot remain on the primary email server indefinitely. Since few email messages are accessed after a few days, moving messages from expensive, high-performance storage on the server to a lower tier of archival storage makes sense. Email archiving software should be able to initiate this data migration. Large email movements can impact storage performance, so if you've got a demanding storage environment, be sure to evaluate performance issues as well.
Index and search features. It's not enough to move aging email messages onto archival storage; it's critical to locate specific messages, attachments and threads, and do so quickly. An email archiving tool can attach relevant metadata to email messages, building an index that can be searched later. You need to understand how email data is indexed and then test the search features for ease of use and performance, especially as the number of messages and the size of the index scales up into millions of items. Make sure the search results are presented in an organized manner that is most appropriate for your organization.
Security. An archive needs security features to prevent tampering with or deleting email and to ensure that the archive remains a viable resource during litigation. Authentication features ensure that only a limited number of authorized personnel can access the archive. Audit trails and logs should be detailed enough to track access and all activities related to each email, including automatic tasks like migrations and lawful deletions. If the email archive tool lacks its own policy manager features, it will need to integrate with your current policy manager in order to enforce retention and deletion policies. Litigation hold features should also be included to prevent movement or deletion of any messages involved in litigation.
Integration with other archiving tools or systems. An email archive tool that does not include data migration and archive storage capacity will need to interoperate with other third-party archive software and archive storage systems. For example, an email archive tool may install on an Exchange server, but the archive software may pass the aging email to an EMC, HDS or other storage system.
Integration with data protection. Archives are not backups; archived email should be included in your organization's data protection plan. Even though disk-based archive systems rely on RAID for local data protection, a storage administrator may opt to perform periodic backups of the archive to tape or VTL, or replicate the archive to a remote location for offsite storage. While the initial backup of an email archive may be time-consuming, the archive itself only changes as new data is added, so subsequent backups can be executed using delta differencing or other approaches that capture only the new content in the archive.
Data reduction features. Since archives can become huge over time, data reduction features such as compression and data deduplication are useful to keep the sizes of archives manageable. Compression and data deduplication remove redundancy by storing a single iteration of a file, block or byte. For example, data deduplication can achieve effective compression rates of up to 50 to 1. Note: Data deduplication works best when implemented on the storage system or archive appliance and allowed to operate on stored data over a period of weeks and months -- ideal for long-term email archives.
Scalability. As the number of archived messages and attachments grows, the sheer amount of storage and overall index sizes can affect search performance. When evaluating an email archiving tool, test the maximum size of the archive and the processing speed (ideally under taxing conditions). Mathon's email archive appliance supports up to 10 million documents, while the Exchange archive product from AXS-One can process 30 GB to 200 GB of data daily. Identify any capacity and performance limitations early to ensure that the product will meet needs as it fills up over time. Note: If the email archive tool is processing data on a third-party storage system, data exchanges with the email archive server may impact the performance of the storage infrastructure.
Hardware requirements and the role of server virtualization. While deploying standalone archive appliances will require little setup, most email archiving software requires a server that meets or exceeds minimum requirements. If server virtualization has been implemented, you'll need to verify that the email archiving software can operate on a virtual server. Also, allocate enough virtual server resources to meet peak processing demands.
Below you'll find product specfications for these email archiving products.