1. What is Data center?

  • Data center are specially designed buildings or premises in buildings that are used to house computer systems and their components, such as servers, telecommunications and storage systems. In general, it such service presumes large quantities of  power, communication connectivity, instruments for monitoring the condition of the room and security devices, and those devices (servers, etc.) where there are critical business applications or databases.

2. What is Podatkovni centar Križ?

  • Podatkovni centar Križ - a brand of the company "Podatkovni centar Križ d.o.o." used for the recognition of all the data centers they built and / or manage. In order to ensure recognition Podatkovni centar Križ name is used, and that name symbolizes high level of quality and safety of ours data centers.

3. What is TIA 942 or Tier Classification?

  • TIA-942 standard contains recommendations relating to the design of the space reserved for the data center or room systems, structured cabling and alignment with standards and Tier environment. TIA is the usual abbreviation for the Telecommunications Industry Association and operationally the word is about the Association that works for 20 years proactively prescribing internationally recognized standards that ensure a certain level of design, installation and operational demands on infrastructure for data and telecommunications systems. In 2005. TIA's most recent list of prescribed quality and safety expectations just for the data center called TIA-ga 942nd TIA-942 provide qualitative details of layout and design of the building, cable infrastructure, details related to the environment and energy level Tier degrees of quality.
  • Tier classification refers to the description of data center infrastructure by levels, in order to maintain a certain level of effectiveness of the entire data center. Tier classification distinguishes between data centers from scale 1-4 where the Tier 1 data center stands for less than quality, and Tier 4 data center is of the highest quality. Depending on the design and installed equipment Tier Classification defines the level of availability of the data center. Tier 1 level of availability guarantees availability of at least 99.741% annually or up to a maximum of 22 hours per year of unavailability. On the other hand, Tier 4 data center should not be unavailable for more than 0.4 hours per year (or 99.995% availability per year).

4. What is ITIL?

  • Information Technology Infrastructure Library (ITIL) - a set of practices for IT service management (ITSM) that focuses on the alignment of IT services with business needs. In its current form (known as ITILv3 and ITIL 2011 edition), ITIL is published in a series of five core publications, each of which covers an ITSM lifecycle stage. ITILv3 supports ISO / IEC 20000 (previously BS15000), an international standard of service management and the standard for IT service management, although differences between the two frameworks do not exist.
  • ITIL describes procedures, tasks and checklists that are not organization-specific, and is used by all agencies which want to measure and improve the minimum level of expertise. ITIL enables organizations to establish a baseline from which to plan, implement and measure the quality level for the organization of its work. It can also be used to monitor compliance and measure progress in the business.

5. What is ISO and what ISO standardization does Podatkovni centar Križ apply?

  • ISO stands for International Organization for Standardization. The company is headquartered in Geneva (CH) and was founded in 1947 and has prescribed 19,000 internationally recognized standards on a global level. Their ISO standards cover a range of areas of activity, such as technology, business quality, food safety, computer standards, health care, etc.
  • Podatkovni centar Križ intensively works on the implementation of several ISO standards, which are essential to the quality of business in general and for data centers. The word is about standards: ISO 9000 (quality management), 14000 (environmental management), 27001 (information security) and 20 000 (service quality management and service).

6. What is seizmic zone and why is it important for the data center?

  • In  2009 Croatian Government adopted the Risk Assessment from natural and technological disasters and technical disaster. Assessment and care of her promptness are the duties  of National Protection and Rescue Directorate (NPRD). Among other things, the document generated at almost 80 pages gives the lists of the history and assessment of vulnerability of each area in RC. National threats posed by floods, earthquakes, other natural causes, but also technical and technological disasters, nuclear hazards, and epidemiological and sanitary disasters.
  • And though it's impossible to estimate the date and intensity of earthquakes (and floods), certain elements of threat can be prevented. DC carefully chose locations for its data centers taking into account that they are stirring in the lower zones, the possibility of flooding the area is little or no, that is not located near military installations or industry that could be a potential threat to data centers. It is important to note that the city of Zagreb located at substantially jeopardizing earthquake zone (seismic zone 9), whereas the data centers are located in earthquake zone 7. According to NRPD in seismic zone 9 represents a very high probability for a desolating earthquake, while in the seismic zone 7 there is a high probability of a severe earthquake.

Seizmička karta Hrvatske

7. What is redundancy?

  • Redundancy (lat.) formal definition (redundancy), an increased number of symbols of a message without increasing amounts of information, in order to transfer a safer and better control of communicating information (due to "noise in the channel.")
  • In information technology, the word redundancy means duplicity. Redundant power supply means that the device or infrastructure has two sources of power. Redundant links represent a safety for users to access the data in situations when there is a break in one of the links, and automatically redundant link takes over the overload.Each institution which, colloquially, cannot be offline or in order that the interruption in availability is minimal, which depends on the availability of infrastructure. An example of such situation is easiest to imagine in commercial banks and business in which immense damage can be caused if a complete transaction system of a bank would be unavailable for several days, especially few weeks. Therefore, the IT world takes into account the maximum redundancy to provide and ensure end users uninterrupted access to data or services, regardless of the potential damage to the system. To achieve this, it is necessary to form a redundant option for each of the segments crucial for the continuation of operations - power, links, uninterrupted power, generators, etc.

8. What is virtual infrastructure?

  • Virtual infrastructure is infrastructure located on the physical hardware, but virtualized in order to deliver services as well as physical. Using virtual infrastructure, users typically save 50-70% on overall IT costs consolidating available resources and delivering highly accessible servers. Virtual infrastructure shows much greater flexibility in scaling needs and through them resources, applications and servers are delivered, when and where they are needed.

9. What is Iaas, Paas and SaaS?

  • Infrastructure as a service (IaaS) - user uses the basic computer resources such as processing power, storage and network components in a virtual environment. The user controls the operating system, applications and possibly networking components such as firewalls, but has no control over the infrastructure cloud. Examples of such services are Amazon EC2, GoGrid, etc...
  • Platform as a service (PaaS) – user uses virtual hosting services for their applications. The user controls when applications are launched, and eventually is provided with some control over the hosting service. However, has no control over the operating system, hardware or network infrastructure on which the application runs. An example of these services would be the Google App Engine.
  • Software as a service (SaaS) – user uses the application from virtual infrastructure, but has control over operating systems, hardware or network infrastructure on which the application runs. Some examples of services include Salesforce.com, Gmail, Google Apps, GoToMeeting, etc...

10. What do marks such as N +1, 2N and / or N +2 mean?

  • These abbreviations relate to terms in data center business and describe minimal or desirable number of devices and systems that guarantee the availability of the infrastructure.
  • 2N - Redundant model that ensures that each component of the system has a reserve (backup) in order to achieve the effect in which there is no risk of crashes (no single point of failure).
  • N +1 - Need or +1 redundancy concept where capacity is configured to include a capacity that is used, but there is a spare which is activated if primary capacity falls.
  • N +2 - Need +2 or redundancy concept where capacity is configured to include a capacity that is used, but there are 2 spare which are included if primary capacity falls or a third case involves in the case of fall of the first two.

11. What is SLA?

  • Service-level agreements (SLA) - is part of a service contract where the level of service is formally defined. In practice, the term SLA is used to contracted delivery time (of service) or performance. For example, data center Tier 3 levels of quality service provided collocation IT equipment at the SLA level to guarantee the availability of data from the same IT equipment at least 99.982% per annum and up to 1.6 hours per year how much data would be were unavailable or according to the SLA parameters were measured over / under agreed.

12. What is collocation?

  • Server collocation service enables to place servers or other types of IT equipment in the appropriate space (commercial Data Centre) with a direct connection to the Internet backbone. The service is designed for companies that have special requirements for accommodation of their websites or business applications, databases, archives and more. Respectively, these are the companies that do not have or do not want to have their own system rooms or smaller data centers.

13. What amount of electrical energy is used by DataCross data centers?

  • The total capacity of the data center will be the Jastrebarsko 4mVA.

14. What type of optical connection do DataCross centers use?

  • Podatkovni centar Križ data centers are using two independent optical routes to two separate nodes in Zagreb. Transmission capacity on each route is 160 x 10 G Fibre Channel (2,4,8,10 G) Ethernet to 10G and all lower speed on L2 or L3.

15. What is dark fiber and what are Ethernet links?

  • Dark fiber - speed data transfer technology that is based on light impulses that travel glass or plastic cables. Fibre optic links transmit significantly more data than conventional connections such as the copper wire.
  • Ethernet (IEEE 802.3) - a network technology for LANs, based on frame mode. That is, the data is sent in packets that are adapted to send over the network. Ethernet, also known as IEEEs 802.3, became the most widespread standard for networks that began to ascend the early 1990s until today, where he holds the primacy, and has almost completely replaced other networking technologies for LANs such as Token Ring, FDDI and ARCnet.

16. What is CIX?

  • Croatian Internet eXchange (CIX) is a Croatian national center for the exchange of Internet traffic housed in the SRCE – Sveučilišni računski centar (University Computing Center), and is open to all Internet providers in the Republic of Croatia.
  • CIX in technical terms, is a unique physical meeting point of telecommunications channels and network equipment of CIX member. This is the place where you can exchange data between all CIX member in accordance with their bilateral agreements.
  • Establishing direct channels of communication between the Croatian Internet Service Providers big savings in data exchange among Croatian Internet users are achieved.

17. What is DWDM device?

  • Dense Wavelength Division Mulitplexing, ili DWDM - refers to the optical signals multiplexed within the 1550nm band that would affect the ability (maximum usage) and price (profitability). Erbium doped fiber amplifier (EDFA) are used, which are effective for wavelengths of about 1525 - 1565nm (C-band).
  • DWDM devices are used to achieve passing of 16 times more data through one pair of optical fibers by multiplexing and amplification, than would be possible without DWDM device. This is achieved by passing each set of data through a different wavelength. It is important to note that DWDM device should be out on each side of the optical fiber - one that multiplexes data by 16 times, and one that recognizes that information and is able to distinguish between wavelengths and spectra.

18. What is a UPS?

  • UPS (Uninterrupted Power Supply) - is a simple and effective system for the neutralization of interference in electrical network, in order to ensure quality and continuity of powering devices, regardless of the operating conditions of electrical networks. The devices maintain a stable voltage and interference filtering. Using rechargeable battery power, connected devices are also powered, even in the case of power failure.

19. What is NOC (Network Operations Centre)?

  • NOC (Network Operations Centre) - a central location for monitoring infrastructure and the space where the operators on duty respond to an alarm or notification based on the problems in the system. The team that takes care of the operation of the system may contain over several experts in each shift - for example, one NOC team in the data center can have a system administrator, network experts, engineers and energy experts, and staff for their physical safety.

20. What is PUE (Power Usage Effectiveness)?

  • PUE is in fact energy efficiency ratio , used to evaluate effectiveness of power usage with as less wastage into other unusable forms.
  • PUE is calculated by dividing the total energy consumption of the data center with the consumtion of IT equipment, as defined by the Green Grid.
  • Podatkovni centar Križ centers are designed to achieve PUE ratio between 1.6-1.7, depending on the degree of utilization of general capacity.

21. What is a server rack?

  • Rack or server cabinet is a metal cabinet that is used for the installation of individual servers, disk drives, communications equipment and the like. Racks typically receive up to 42 Units - individual devices. A closet serves as a servers carrier and provides design and equipment for servers to work. In addition, the cabinet serves as a quality cabling for each server and data storage because racks always have a door that can be locked, and the common case is locking cabinets with biometrics or smart card readers.

22. What is (server) Unit?

  • Frequently used acronyms is U. Example, 1U  represents one server or one Unit that is placed in the server cabinet

23. What is Disaster Recovery?

  • Disaster recovery (DR)  - set of processes, policies and procedures related to preparing for recovery or continuation of technology infrastructure critical to an organization after a natural or human-caused disasters. Where recovery focuses on the IT or technology or systems that support business functions.

24. What is Business Continuity?

  • Business Continuity -  the activity performed by an organization to ensure that critical business functions are available to customers, suppliers and other entities that must have access to these functions. These activities include many daily tasks such as project management, system backups, change control and help desk.

25. What is CCTV?

  • CCTV is an acronym for "Closed-circuit television" , closed TV system that normally refers to video surveillance system.

26. What is HVAC?

  • HVAC stands for "heating, ventilation and air-conditioning" , the mechanical part of the data center in terms of heating, ventilation and space air-conditioning.

27. What does the mark Carrier Neutral mean?

  • It is a term popular in the world of data centers. It is a situation in which a company that manages the data center does not favor any of telecommunications operators and offers to all operators the same approach, the conditions and possibilities of cooperation.
  • Podatkovni centar Križ centers are Carrier Neutral.

28. What is SCADA?

  • It is an acronym of Supervisory Control and Data Acquisition - industrial control system that controls and monitors the industrial, infrastructural and facilities process.

29. What is White Space?

  • White Space is an area with a high floor where the servers are located. This term refers only to the space to accommodate the equipment and does not include other parts of the infrastructure of the building in which the data center is located.

30. What is Uptime Institute?

  • Uptime Institute is an internationally recognized organization that is central to success criteria and quality data centers. Documents produced by the Uptime Institute are internationally used for so-called  benchmarking process when it comes to data centers.