Michael Rößler not available until 12/31/2021

Michael Rößler

Linux Specialist

not available until 12/31/2021
Profileimage by Michael Roessler Linux Spezialist from Hamburg
  • 22045 Hamburg Freelancer in
  • Graduation: not provided
  • Hourly-/Daily rates:
  • Languages: German (Native or Bilingual) | English (Native or Bilingual)
  • Last update: 29.10.2020
Profileimage by Michael Roessler Linux Spezialist from Hamburg
Operation Systems
Linux, Solaris, MacOS X, Microsoft Windows (3.0 - 10)

VMware ESX 3.x und Vsphere 4 – 5.5,
VMware Server, Workstation and Fusion,
Solaris Container, Xen, Docker

Volume manager
Linux LVM, SDS, Veritas Volume manager

Veritas Filesystem, GFS (Clusterfilesystem unter Linux)

Connectivity of Solaris and Linux servers

Installation and configuration of middleware systems:
Weblogic, JBoss, Tomcat, Glassfish, Payara, Apache, LAMP

Postfix, Zimbra, Majordomo

Shell, Python, Perl

Nagios, BMC Patrol, HP Openview

Lucent VitalQIP, Bind

Veritas Netbackup

Heterogeneous Networks

Automatic Installation
Jumpstart, Kickstart, PXE-Boot with Diskless Clients

Software Packaging
Creating software packages for Solaris and Linux (RPM)

Version control software
Setup and usage of CVS, Subversion and Git servers

IBM Tivoli Provisioning Manager (TPM)
Public Services
01/2019 -
Main focus: Senior Application Support Management
- Management of applications in production and pre-production
- Administration of JBoss, Tomcat and Apache / PHP based applications running on Linux and MySQL or Oracle database
- Change-, Incident- and Problem-Management based on ITIL with Remedy
- Proble analysis and troubleshooting with Linux command line tools
- Developing, maintaining and enhancing Shell-Scripts and Python-Scripts
- Enhancing and updating the technical and organisational documentation

09/2017 - 12/2018
Main focus: Senior Application Support Management
- Management of applications in production and pre-production
- Administration of Websphere and IBM Business Process Manager based applications running on Red Hat Linux and Oracle database
- Change-, Incident- and Problem-Management based on ITIL with HPSM
- Performance analysis and troubleshooting with Dynatrace and Linux command line tools
- Developing, maintaining and enhancing Shell-Scripts and Python/Jython-Scripts
- Enhancing and updating the technical and organisational documentation

Aerospace Industry
05/2017 – 08/2017
Main focus: Senior IT system and network administration
- Administration, configuration and supervise of the company network and servers running under Linux (Red Hat, CentOS, Debian)
- Administration of the Active Directory and Exchange server in an Office 365 environment
- Administration and configuration of the virtual infrastructure running under VMware vSphere and Proxmox
- Migration from Proxmox to VMware vSphere
- Proposal for a new IP telephony system
- Administration and support of desktop PCs running under Linux, Windows or Mac OS
- Administration and configuration of network systems (Switches, Firewall, VPN, IP Telephony)

International mail order company
08/2008 – 02/2017
Main focus: Management of development and testing servers running on SuSE Enterprise Linux
- Collaboration in a project to migrate the development, testing and production systems from hardware to virtual machines
- Customising the Linux system to match the requirements of the virtualized environments
- Conceptual design an implementation of a security concept involving a jump server to access the virtualized development, test and production systems with the integration of an SSH key management system
- Development of a web-based SSH key management system with roll-based access authorisation for servers
- Proof of Concept of a virtualisation for the development and testing systems
- Evaluation using container technologies (Docker) instead of virtual machines based on VMware vSphere
- Coordination and supply of testing environments during all phases of testing
- Administration of a Majordomo system with a couple of hundreds of mailing lists
- Coordination of software projects with third-party systems for the diverse testing phases
- Conceptual design of a virtualisation platform based on VMware ESX, including a business case, for the development and testing environment
- Identification of potential technical, functional or organisational gaps as well as options to improve processes in the department
- The composition of practical ideas for improvement
- Improving and updating the technical and organisational documentation

Investment bank
11/2001 – 07/2008
Main focus: Enterprise Computing und System Engineering
- SAN: RDAC with StorageTek and HDLM und Device Mapper Multipath with Hitachi Data Systems under Red Hat Enterprise Linux (RHEL)
- Collaboration in implementing of CMMI Level 3
- Migration from Inhouse-Provisioning-System to IBM Tivoli Provisioning Manager
- Implementation of a global LDAP solution for the Frankfurt branch
- Global Build Management
Rollout- and Migration strategies for the worldwide usage of Global Builds
Integration of global database builds with global operation system builds
Maintenance of the existing Global Builds
- Global Linux Build based on Red Hat Enterprise Linux, conceptional design and implementation of installation methods, maintenance mechanisms, SOX compliant test scenarios with the aim to develop a Linux build to be used in all international branches
- Administration and setup of cluster systems with diskless nodes for risk analyses
- Administration and setup of redundant servers for electronic marketplaces
- Disaster Recovery:
  Planning, development and realisation of disaster recovery test and procedures
- Migrating several software projects from Solaris to Red Hat Enterprise Linux
- Oracle RAC Proof of Concept
  Oracle 9i on Red Hat Advanced Server 2.1 in conjunction with GFS (Sistina / Red Hat) cluster filesystem and SAN
  Oracle 10g on Red Hat Advanced Server 3 und SAN
  Failover tests of RAC-Nodes, DR-Tests with the simulation of SAN interruption Documenting the PoC

- Development of scripts to automate the deployments of new software releases in web-applications
- Development and implementation of a logging server (Client-Server) to store audit relevant data in the scope of SOX
- Conceptual design and implementation of HA systems with shared SAN storage, IP takeover and automation by using event handlers
- Writing system documentation and operating manuals, mainly in English
- Moving servers in the context of relocating data centres
- Connecting the HP hardware monitoring to an existing system monitoring software via SNMP
- Developing and implementing automated server installations
- Implementation of DNS servers within the scope of network segregation
- Evaluating new hardware, performance tests, integration tests, comparison with systems already in use and writing management summaries for decision making
- Evaluating Solaris 10 on Intel x86 and AMD Opteron servers, the main aspect was to determine if Solaris 10 can be used instead of an enterprise Linux distribution
- Administration of servers running on
  Solaris 2.5.1 to Solaris 10, Red Hat Advanced Server 2.1 to 5, SuSE SLES 8
Other projects
04/2003 – 05/2005
- Migration from Microsoft Windows to Linux on the desktop (law offices)
- Monitoring distributed systems with Nagios, programming of plugins and event handlers
- Administration of distributed systems with Cfengine
IT training company (as an employee)
04/2000 – 10/2001
- Planning and conceptual design of new training
- Training customers in Linux (system administration, network administration, heterogeneous networks, security)
- Preparing and maintaining the training material
- Setup and management of the VUE test centre
Electricity supplier
06/1999 – 12/1999
- Migration from Novell to Linux / Samba
Programming under Linux and Windows
- Documentation of software projects
International IT hardware manufacturer
05/1996 – 03/2000
- Presales-Consulting for server, network components and telecommunication hardware
- Supporting Sales Representatives
- In-house training and presentations for distributors and reseller

1993 – 2000
- Implementation of Linux firewalls and Linux servers in heterogeneous networks
- In-house training for users on Microsoft Windows and Microsoft Office
Internationally available. 
Preferred: Norther Germany, Ireland, United Kingdom