||Trainer for LPI Linux courses
||Trainer for RedHat Enterprise Linux 7 Certified System Administrator courses.
||Vesting Finance, Hilversum
||Migrating RedHat Linux systems to external cloud infrastructure, documenting and
improving system-configuration using Ansible configuration-management tooling
||SpeedCast Europe, Rotterdam
||Builing a mail and office infrastructure for offshore shipping, optimizing
for minimal data transfer over sattelite links
||Logius, Den Haag
||Logging and Monitoring Administrator for Logius / MijnOverheid.nl, building
and maintaining a Logstash/ElasticSearch/Kibana stack using Ansible configuration management.
||Trainer for various Linux and TCP/IP courses for Imatica / InternetOpleidingsCentrum.nl,
including a 5 and 10-day Linux courses and sigle-day TCP/IP and networking courses.
||Advo (nee: StepCo) Houten
- Migrate RedHat 5.x systems to RedHat Enterprise 6.4.
- Configure backup-environment for Linux systems
- Troubleshoot RedHat Enterprise Linux crashes on Microsoft Hyper-V platform
||Gave a 1-day training on Apache webservers
||Configure a few RedHat Enterprise Linux systems for a customer of Transfer
||MG Technical Solutions
||Upgrading linux server environment to new major releases.
||Executing an audit of a NagiosXI monitoring environment for a large distributor.
||FloorIS Internet Services
||Setting up a clustered webserver and database server environment for hosting customer
websites based on Red Hat Cluster Suite, Apache, Mysql and GFSv2. Creating a backup
infrastructure for all hosted systems with off-site backups using backupninja, rdiff and rsync.
||Setting up a monitoring infrastructure for a large system-integrator in Utrecht based on NagiosXI.
||Setting up a web-invironment for a Drupal/Apache/PhP/Mysql based intranet/extranet solution
on Solaris. Performance-tuning this environment
||Setting up an Oracle Enterprise Linux system.
Configuring iscsi connection to Equallogic SAN
||Upgrading Suse Linux 9 servers to Suse Linux 10.
||Habufa B.V. Hapert
- Setting up a cluster of RedHat Enterprise Linux 5.7 systems on HP BL460-G7 systems.
- Configuring and tuning multipathing and iscsi connection to HP Lefthand SAN
||Greetz B.V. Amsterdam
||Fully manage large outsourced IT environment running RedHat Linux, CentOS, Ubuntu, Redhat Cluster Suite, RedHat Global
Filesystem, F5 Load balancers and Tomcat application servers
- System monitoring, alerting and incident response
- Replace EMC FC-based SAN with Dell Equallogic ISCSI san
- Replace Cisco routers with Juniper J-series routers
- Virtualize exising linux environment on KVM/LibVirt infrastructure
||As a consultant for Snow I have worked at many major multinational clients in the Telecommunications, Banking and
Minerals sectors, maintaining complex Unix-centric environments.
||Migrating e-commerce website to a new colocation facility
Daily maintenance of HP-UX, SuSE Linux and RedHat Enterprise Linux systems.
Designing, building, testing, implementing, maintaining and documenting OpenLDAP based central directory for the multi-vendor Unix environment (HP-UX and Linux)
Migrating one of the Tele2 Datacenters to new racks and cold-corridor’s without long downtimes for involved applications
Maintenance of the backup environment based on EMC Networker with both physical tape libraries and VTL’s
||WineCare Pro, USA
||Building a custom barcode printing web-interface
||Installing a Solaris 9 machine and some troubleshooting
||T-Systems, Den Haag
Migration of Tru64, Solaris, HP-UX environment to AIX 6 LPAR’s and Solaris 10 Zones.
Designing, building, testing, implementing, maintaining and documenting OpenLDAP based central directory for the multi-vendor Unix environment (Solaris, AIX and Linux)
Building kickstart environment for RedHat Linux virtual machines
System administration on Apache/Tomcat clusters, F5 Load balancer, cisco routers and firewalls.
System maintenance of Solaris 8 and Checkpoint Linux systems
Scripting utilities for RSA-ACE server (tcl) automation
Incident handling on DNS, firewall and management systems
Migrating sudo installation to centralised LDAP-based configurations
Auditing systems and writing audit-checking framework and scripts to report on security related settings on Solaris 8 systems.
||Shell E-P, Rijswijk
System maintenance of shells custom Linux desktop and server systems
Building a server, desktop, and office-frontend environment based on OpenBSD for use im embargoed countries.
Environment consisted of OpenBSD, OpenOffice, Gnome, cups printing, Exim mailservers, centralised kerberos
authentication, ldap, version-controled configurations (svn) and automated package-building, testing and installation.
Now: Tele2 Zakelijk
Design a centralized backup infrastructure for management systems, customer systems and broadcast systems.
Design and implement a configuration management system for hardware in the versatel testlab.
Design and implement a resource reservations/booking system on top of the configuration management system
Design system sub-section of Versatel’s Narrowcasting product
Design and implement reporting, management and configuration tools for Versatel’s ADSL2 Triple-Play product.
||Gaz De France, Zoetermeer
Now: GDF Suez E.P.
Gaz de France Netherlands has a small permanent IT department that only handled the network and windows system.
It also has some Solaris servers that run it’s mission critical application by Landmark Graphics. My job was
to administrate these Solaris systems, migrate the Landmark software to a new release, increase performance of
the Landmark systems and support the users of those systems.The performance of the Landmark system was increased
by tuning kernel parameters, moving data to different raid-arrays and setups (raid1 vs raid5), upgrading hardware
and offloading applications to seperate servers or to the desktops. I also standardized a Linux desktop system
for use with the Landmark application, made a plan for a new management network and remote administration system.
UPC is legally required to protect it’s information and have asked for assistance in installing a consistent
and current version of Secure-Shell to all it’s Sun Sparc (Solaris 7,8,9) based systems. An inventory of
currently running SSH versions was made, applications and users using these versions were identified and a plan
was written to migrate all systems to a new site-wide consistent version of Secure Shell.A custom packaged version
of OpenSSH was created, fullfilling all UPC requirements and wishes regarding it’s configuration. This packaged
version was then installed on UPC’s systems, old settings, users and applications were migrated to the new
version while maintaining availability to the users of the production systems.
After numerous contract extensions working for the Unix department I moved to the Networking department. My jobs
- Configuring Avaya, Olicom and Cisco switches and routers (Tokenring and Ethernet)
- Writing network-management tools using expect, perl and shell scripts
- Analyzing network problems (sniffing, routing)
Together with some (ex-)collegues I have set up a non-profit, private ISP. Together we handle all tasks a real
ISP handles. We have placed a unix system/router on a AMS-IX location,
setup BGP routing on IPv4 and IPv6, requested a AS-number and IP space from RIPE, setup
peering with other ISP’s and provide mail, usenet, web and shell access to ‘sponsors/users’.
We have also joined the Domain-Registry organisation, so we can request and
administrate our own .nl domain named without relying on other ISP’s.More info on http://nerdcentral.nerdnet.nl
The belastingdienst (revenue service) needed temporary system administrators to assist it’s personnel during
a migration traject to a complete new computing environment, based on AIX. My task was to assist the local
administrators and solve all incidents in the production enviroment while the local staff were on vacation or
on large training projects. The department was responsible for various websites running on HP-UX and AIX systems,
the network equipment (firewalls, routers, intrusion-detection, monitoring) and backups. After several extensions
of the original contract I became responsible for maintaining most of the belastingdienst’s webservers and
supporting systems. Performing (security) updates and performance tuning the AIX and HP systems, monitoring,
IDS and logging.
||Installing MGE’s ups software on Bull AIX systems
||SyConOS IT, Emmeloord
Installing, testing, documenting and maintaining the company mail server, based on a SuSe linux system,
running the courier-mta mail suite. The server provides SMTP, POP3, IMAP, webmail, a support website and
mailinglists for the employees of SyConOS. The mailserver makes use of various encryption protocols to provide
secure access to the e-mails (TLS, SSL, over either IMAP, POP3 or SMTP). Various methods are used to limit
the amount of spam received on the system by using multiple RBL lists, bayesian filtering and analysis of
e-mail content to discover spam.
||ABN-Amro Bank, Amsterdam
System administration and technical lead on security projects for the ABN-AMRO’s e-Banking systems and internal
unix (IBM and HP) environments. Tasks included:
- Deciding on security enhancing facilities to implement and enforce
- Building and testing these facilities, automating installation and configuration.
- Documenting configuration-management system
- Daily administration of IBM and HP server-farm (250+ nodes)
- Implementing custom patched versions of OpenSSH, OpenSSL, SuDo
- Supporting junior system-administrators and customers
The VVAA HP server environment had been without maintenance for some time and needed a serious overhaul and
checkup. VVAA wanted to give administration of these servers out to a third party service provider. Before
this could be done the environment needed to be cleaned up and analysed. The following actions were undertaken
so the third party could take over maintenance and administration for the HP server environment.
- Writing planning for analysis and cleanup.
- Doing security assesment of the systems and environment.
- Writing ‘administrative’ documentation.
- Writing security advisories.
- Creating and documenting backup procedure HP systems (Ignite tapes)
- Documenting problems, planning fix-actions for these problems, documenting and fixing defects.
- Analysing performance and creating tools for gathering performance data from the HP server environment.
- Creating trend-graphs from gathered performance-data using self-written tools.
||ABN-Amro Bank, GTS
My team was responsible for managing the test environment for the GTS Portal, doing application intakes,
testing their installation in the test environment, documenting these actions and helping the applications
for a smooth transition to the production environment. The environment consisted of various HP-9000 systems
and using (amongst others) the following software:
- Iplanet Enterprise Server
- Iplanet Proxy server
- Apache webserver
- Websphere Application server
- SilverStream Application server
- Silverstream E-Portal
- Oracle 8
The ABN’s use of the Silverstream Application server on the HP 11.x platform was (one of) the first
worldwide, so we encourered a lot of problems and issues with the application which we resolved in cooperation
with specialists from Silverstream.
|2000 – 2001
Setting up and managing various company websites on HP-UX 11 and Debian GNU/Linux.Managing Sun Oracle8i database servers
Installing, managing and upgrading the production and test/development environment for ABN-Amro’s new
import/export portal website maxtrad.com (The maxtrad.com website has since been discontinued by the ABN Amro).
- Installing HP-UX 11.x
- Installing Netscape/IPlanet Enterprise server
- Installing Oracle support software (Java, ODBC)
- Installing and managing test servers
- Setting up monitoring system
- Setting up backup system
- Negotiating SLA terms for hosting
- Performance tests / Load tests
- Performance tuning
Other tasks included:
- Setting up and maintaining the projects gateway/proxy and firewall systems
- Troubleshooting and support for the unix systems and network
- Instructing the other sysops about the unix systems.
Writing action-plan, and executing consulting tasks to increase availability of HP-9000 servers.
Tasks executed include:
- Setting up disk mirroring with HP’s volume manager (LVM)
- Setting up a dedicated backup system
- Updating legacy LVM configuration while maintaining full availability during office hours.
||Emergency restore from a crashed bootdisk on large HP-UX 10 fileserver with corrupted
Legato Networker backup indexes.
Complete process from idea to deployment and client-consultation of a ‘network-appliance like’ fileserver
(unix-based) for Apple MacIntosh networks
Developing and implementing a web-based system for managing internal documents, procedures and
instructions. A password protected system where employees of Ptt-Post can lookup and modify (if allowed)
documents via a web-interface. Tasks included programming the system, installing webserver, database (MySQL)
and scripting language (PHP). Entire system developed using a revision control system, and fully documented.
Second and third level HP Unix support for production (500+ nodes) and test (50+ nodes) networks.
- Troubleshooting: Disk crashes, server crashes, hardware errors, disk-full.
- Account management: Creating and deleting user and application accounts, resetting passwords.
- Software Distribution management: Installing and removing software (universally) on remote HP sites.
- Support for application developers
- Installation and setup for new servers
- Setting up and maintaining server-configuration database
- Scipting, building tools, documenting
- Managing NIS, DNS, Bootp, Inetd configurations
- Managing backups and restores
||Executing Millenium upgrade for the 500+ node HP-UX network (Upgraded from HP-UX 9.04 to 10.20.41).
Setting up 50+ remote Legato Networker backup systems on HP-UX using HP SureStor DLT Libraries.
All 50+ systems use single setup script and are fully managable from the central management site.
||Unix Support Nederland
under Netscape SuiteSpot on a HP700 system. The system stored customer and employee information
in a Informix database.
Designing and installation of a proxy machine with on-demand dialing for the company internet
connection. The system also had a dial-in facility so employees could connect from outside of the
company and still be able to access the corporate network directly. Linux machines have been used
for proxy, gateway, firewall and e-mail systems, Cisco routers and modem-pools were used for the connections.
||Assisting in the setting up of a redundant NT-cluster of webservers, using hardware VPN for maintenance.
||Installation and configuration of Checkpoint Firewall-1 in combination with the eSafe virusscanner
so all Internet traffic was automatically scanned for virii.
||Vermeulen & Hollandia
||Setting up linux e-mail server and dial-on-demand internet connection.
||Unisource Business Networks
Builing a web-based DNS updating program for UBN’s customers allowing them to update the secondary
DNS entries themselves, saving UBN’s employees a lot of time and also speeding up changes. System
was built to help about 1000 customers that used UBN as a DNS secondary.
||System administration for this small start-up ISP. Tasks range from system setup to creating
web-pages and setting up accounts to doing crash-recoveries etc.