Hello,
i'm a sysadmin with more then 5 years experiance in TLC italian enterprise company, focused on Mission-Critical services.
I work daily on operating system GNU/Linux, RHEL, CentOS, SLES (SUSE Enterprise) and Ubuntu Server and on critical Cluster configurations made by different stacks like Pacemaker/Corosync/Heartbeat (RHCS, HAE), DRBD replication. Basic skills on Veritas VCS and HP ServiceGuard. Lots of experiance about OS hardening/security, SSH hardening and some fail2ban configuration.
Expert skills about virtualization via VMware vSphere and Citrix XenServer, network aspects (virtual switches, VLANs, trunks, port-channels, ecc.) and about resource management (memory ballooning, CPU contention, cpu/memory reservation, ecc.)
Really good knowledges of Apache2, Nginx, Oracle MySQL, PostgreSQL, uWSGI, JVM (Xmx, Xms).
I setup projects concerning IT server monitoring using open source software like CACTI, OpenNMS and VMware vFabric Hyperic HQ and setup backup systems using Amanda/Zmanda platform.
Good skills on managing services of different kind of Cloud Providers like Aruba (IT), Linode (FR), OVH (FR), AWS (Worldwide), BlueLightHost (UK), Contabo (DE).
I work on XenServer environments since XenServer 5.6 to 7.0. I did different configurations (standalone, pools) and doing daily maintenance and delivery. Lots of knowledges on backups, advanced command line, networking (VLANs), SAN, NFS, etc. Now i'm working on a 3-host pool infrastructure with shared SAN.