Sean Carolan

Linux System Administrator

Skills

Professional History

Senior Systems Administrator: Installed, configured and provided 24x7 support for a production network of 160 Red Hat Linux servers. Responsibilities included setup, configuration and monitoring of Apache, DNS, NFS, FTP, MySQL, and web-based java application clusters. Configured HP SIM monitoring software to alert system administrators to hardware failures for both Dell and HP hardware. Upgraded busy four-node sendmail cluster from Red Hat 6.2 to RHEL 3.9 with zero downtime required. Deployed BackupPC as a backup solution to ensure that all production systems received regular incremental and full backups. Created custom kickstart files and bash deployment scripts to reduce new server build times from several hours to less than 20 minutes. Converted several dozen old servers to VMWare guests, saving the company thousands of dollars in electricity and overhead costs. Installed cfengine across the entire production environment to allow policy-based management of all hosts from one central location. Reduced unplanned outages to ensure 99.5% uptime according to customer service agreements.

Authoria – 6/2007-Present

Linux System Administrator: Setup Red Hat Enterprise Linux servers, configured services, performed security audit and firewall installations. Deployed BackupPC as a backup solution to ensure that all production systems received regular incremental and full backups. Installed and configured Nagios monitoring system so system administrators would be notified via SMS or email when production servers or services were down.

IBM / State of Texas – 4/2007-6/2007

Webmaster / System Administrator: Installed and configured Urchin software on Red Hat Linux servers to analyze web marketing data. Optimized company web pages for getting higher results in search engine listings. Created custom shell scripts to process data and create backups. Configured firewall and security settings on Internet web servers running Apache.

SANS Institute – Kapaa, HI – 10/2006-3/2007

General Manager: Managed sales and IT departments, assisting with administration of Linux servers, including web, email, and intranet/database servers. Oversaw installation of new VoIP phone system that saved the company thousands of dollars and greatly simplified deployment and provision of phone service for new employees.

Aria Medical – San Antonio, Texas – 9/2005-9/2006

IT Manager: Built company’s network infrastructure from one desktop machine with a dial-up modem, to a secure network of 25 hosts with proper firewall, DNS, and redundant network connections. Duties included hardware research, purchasing new equipment, pulling network cables, installing routers and firewalls, setup and maintenance of mail and web servers, user tech support, and backup administration. Replaced sales department’s Windows XP workstations with thin-client solution running Fedora Core Linux, eliminating expensive Microsoft license costs and need for constant spyware and virus removal. Built custom rsync-based backup solution to ensure company data was secure and available in the event of a server crash or data loss.

Aria Medical – San Antonio, Texas – 2/2002–9/2005

Web Developer / System Administrator: Administered all aspects of a small web design company. Managed Red Hat servers running Apache, MySQL, and PHP. Configured and set up sendmail, MailScanner and SpamAssassin for client email accounts. Performed remote backups using custom shell scripts and cron jobs. Monitored servers 24x7 and hardened security firewall against unwanted intruders.

Texas Internet Design – San Antonio, Texas – 4/1998–1/2002

Education

Red Hat Linux Certified Engineer (RHCE) – Certification #804006401020980

SANS/GIAC GSEC Professional

Massachusetts Institute of Technology - Course 21 - 9/1992 – 5/1995