Four primary factors contribute to the increasing need for Exchange Server data management solutions. These factors are the increasing use of email, the growth in size of document formats, the increasing availability of inexpensive raw storage, and corporate and regulatory-compliance requirements.

Increasing use of email. IDC has predicted that the number of email users worldwide will have increased from 452 million in 2000 to 1.2 billion by 2005. The company similarly predicts that email traffic will increase from an average of 9.7 billion person-to-person messages sent worldwide each day (in 2000) to 35 billion person-to-person messages worldwide per day (in 2005). Considering these numbers, the increased requirements for storage and the resulting data management challenge are unsurprising.

Growth in size of document formats. Document formats, especially those produced by Microsoft Office applications, have enlarged file sizes considerably over the past several years. The proliferation of these document types as email attachments has accounted for a considerable increase in storage requirements. A typical Microsoft PowerPoint file can be 1000 times larger than an average text-based email. Microsoft Word files are similarly large (although not quite as culpable as their PowerPoint cousins). Retaining x number of email messages today is likely to demand a significant increase in overall storage than it required several years ago. Mailbox sizes have typically grown over the past several years, and complex file formats stored in user mailboxes now consume significantly more space than do simple text messages. The Radicati Group reports that the size of a basic text email more than doubled between 2003 and 2004, with an average email being 38.1KB and 469.2KB in size (without and with attachments, respectively); attachment sizes having increased annually by 30 percent.

Increasing availability of inexpensive raw storage. Another factor that has contributed significantly to the data management challenge is the sheer availability of raw storage. Many Exchange I/O subsystems are configured for maximum spindle count (smaller Exchange implementations might not be afforded this luxury). As disks have grown in capacity, a pleasant side-effect has been copious quantities of available disk space at a relatively low cost. The Harrow Group’s Harrow Technology Report has stated that 20 years ago, a 20MB disk drive cost around $1200 (approximately $20 per MB), whereas in 2004 a 200GB disk drive cost around $100 (approximately $0.0005 per MB). With this increase in storage capacity and in an effort to address the rising demand for storage, many organizations have set generous mailbox quotas, thus setting the stage for data-management headaches in the future. Mailbox sizes have grown from about 25MB back in 1996 to about 100MB to 200MB today.

Similarly, increases in the performance capabilities of many backup and restore devices have resulted in faster backup and restore times. The earliest DLT tape drives had native transfer rates of about 1.25MBps; modern DLT drives can provide 16MBps transfer rates, and Linear Tape-Open (LTO) drives offer rates of up to 30MBps. These advances in backup-device performance support larger Exchange database sizes, effectively masking a data-management problem.

Regulatory-compliance requirements. With the advent of Sarbanes-Oxley, more and more companies need to implement policies that meet the needs of external regulatory compliance agencies as opposed to simply meeting internal guidelines. In an upcoming article, I’ll discuss how this type of regulatory compliance affects Exchange data management.