While most students were away from campus on spring break, Harvard Arts and Sciences Computer Services (HASCS) completed the third and final stage of its plan to upgrade Harvard's e-mail system.

The improvements, which began in January, were made in response to student and faculty complaints last semester about the speed and reliability of Harvard's e-mail system.

"We [now] have a more reliable system that's more easy to expand and less susceptible to problems," said Franklin M. Steen, director of Faculty of Arts and Sciences Computer Services.

In last week's upgrade, HASCS transferred users' home directories and e-mail inboxes to a new disk array, or data storage system.

The main feature of the new system is to provide "redundancy"--multiple components to prevent a single failure from bringing down the entire system.

"There really is no single piece of hardware that can fail and take out the whole system," said Rick B. Osterberg '96, director of residential computing support. "There are two server boxes, two power sources, two of everything."

The new disk array is also faster than the previous one and offers more room for future expansion. Users' directories currently use about 150 gigabytes of storage space, but the array has a maximum capacity of about 600 gigabytes, Osterberg said.

Steen said the new system performed well in tests, but he said he cannot guarantee that the new system will not have problems.

"You can never foresee problems, but [with the new system] we can recover from the problems much more quickly," he said.

Osterberg said he is "cautiously optimistic" about the success of the upgrade, and said he is withholding further judgment until system usage returns to normal levels today.

Steen said much of the recent strain on the e-mail system has been due to the increasing number of users who use programs like Eudora, which automatically access the mail server at regular intervals to check for new messages.

"We had users who were checking mail over 30,000 times a day," Steen said.

In response, HASCS now keeps a "top ten" list of the users who most often access the mail server and recommends that they change their program's settings to check for new messages less frequently.

"People are not doing this on purpose," steen said. "They're upset that their machines are not being good citizens."

With the completion of the three-stage upgrade, HASCS officials believe they can shift their focus from fixing existing problems to preparing for future needs.

"We think we have migrated from quick fixes [of the existing system] to planning for the future," Osterberg said.