April 2005 -- Volume 2 -- Number 1 -------------------------------------- * Project Data Protection All project data (/n/fs/projectname) now has an additional level of protection against hardware failures. Data is now stored on mirrored arrays consisting of a RAID-5 array and a RAID-6 array. The minimum number of simultaneous drive failures that will result in data loss is now five drive failures across two enclosures from two different manufacturers. While even the simultaneous failure of two drives in a single RAID-5 array is an extremely rare event, this did occur last December. With this reconfiguration, we are protected against a similar failure mode in the future. * UPS Replacement for Room 218 As you have experienced, the power quality in this part of New Jersey is not the greatest and we are susceptible to power outages from time to time. To protect our equipment and data in room 218 from sudden power loss, we use a large uniterruptable power supply (UPS). Our current unit is now over 7 years old and is reaching the end of its useful life. With funding from SEAS, we will be replacing our UPS early this summer. While some of the installation work will require the machine room to be shut down during working hours, we will try to minimize the impact on the department. * Beowulf Cluster As mentioned in the last issue of the Gazette, Kai Li has made a number of his machines available to the department for cluster computing. The cluster went "live" in December with 48 CPUs (933 MHz each). Since December, we have incorporated additional machines and the cluster now has 168 CPUs. For more information, see the preliminary documentation by visiting: http://www.cs.princeton.edu/beowulf * ProofPoint Spam Filter On May 1st, we will roll out a new commercial spam filter from ProofPoint, Inc. This filter actively quarantines spam messages; that is, spam messages are not delivered but are instead held in a quarantine location. Each weekday, users receive a single message containing both a list of the messages waiting in quarantine that the system has determined to be spam as well as instructions for "releasing" (delivering to the user) particular messages. Messages that are not actively released by the user will automatically be deleted by the system in two weeks. We have been beta testing this system since December. Based on our experience, the system has a very low "false positive" rate (very few legitimate messages are incorrectly classified as spam). However, for those who are wary of spam filtering technology, there is a method to place the filter into a passive mode in which it will not quarantine any of your messages. More details can be found on the CS Guide here: https://csguide.cs.princeton.edu/docs/email/proofpoint.php * Security Updates And finally, this is a reminder to keep your machines up-to-date with respect to security patches for both the operating system as well as applications. There have been several important updates to Linux, Mac OS, and Windows over the past couple of months.