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THR Systems a. s.
Jilemnického 3, Zvolen
tel.: +421 650 52 00 00

Branch Bratislava
THR Systems a. s.

Čapkova 2, Bratislava 1
tel.: +421 650 52 00 15

Branch Nové Zámky
THR Systems a. s.

Turecká 36, Nové Zámky
tel.: +421 650 52 00 33

Solutions - Enterprise

RAID Disc Arrays

Data safety belongs to one of the highest priority of every company. We consider only data loss raised by technical equipment failure. Data loss are the most often caused by hard disc failure. it is natural, since it is equipment which is liable to physical depreciation and which is sensible to inadequate manipulation and physical impacts. It is possible to fight such types of data loss by creating RAID disc arrays. The most often used types of RAID disc arrays are RAID0, RAID1 and RAID5, or their combinations.

The RAID0 disc array does not add any safety to your data. It enables only faster access to the data. It utilizes concurrent accesses to more medias in a time. It is possible to add arbitrary many discs to this type of disc array. The aggregate capacity of the array is equal to the sum of capacities of all the discs.

The RAID1 disc array offers more security by creating identical copy of data to another media. It is possible to add arbitrary many discs to this type of disc array. Every disc than contains identical copy of data. This type of array is resistant against failure of all the discs except one of them. The aggregate capacity of the array is equal to capacity of the capacity of one disc.

The RAID5 disc array offers more security by distribution data over discs and by creation of parity sum. This type of array requires at least 3 discs to create. This type of array is able to recover after failure of one of the discs in the array. It's capacity is not so dramatically degraded as in previous type of array.

It is possible to implement all the types of the RAID disc arrays in harware and in software approach. Hardware implementation is more costly but at least in RAID5 implementation is much faster. When using RAID0 and RAID1 arrays, the speed between software and hardware implementation is comparable. We could advice the usage of RAID1 mirroring in the Linux operating system as a low cost and reliable solution for your data safety.

SAMBA File Server

Probably the most often used service in an enterprise network is the file and print server. Linux naturally offers this capabilities. Besides other modern protocols for sharing files and printers it supports also sharing by CIFS protocol, what enables compatibility with majority of nowadays used workstations. Except file and print server Linux has the ability to centrally hold user database. Workstations can authentify users by NIS, Kerberos, Windows NT domain, LDAP and by other means.

Enterprise Network

The workplace is composed of server with operating system Linux and workstations with operating system windows. Server works as a Primary Domain Controller for Windows NT domain. Workstations are added to the Windows NT domain. Users are authenticated against Primary Domain Controller and their passwords are stored in the LDAP server. After successful authentication users gain access to resources which are they authorised to use until they logoff. Every user has his own private disc place. It is possible to grant access to disk places to user groups, for reading and writing separately. Server enable network printers also. Printer drivers are stored on the priter server also. If user wants to print to a printer, he can add it by browsing on the server and clicking the "Connect" button. This action is performed only once and system connects the printer automatically after next logon. This action could be done automatically through the login script.

The users are not binded to a concrete workstation. They can choose which one to use. The roaming user profile is copied from the server after logon and back to server after logoff.

Diskless Clients

Enterprise Network with Thin Clients

Very advisable and time saving solution is the use of the Network Boot Server. It is a server which enables performance to thin clients (the workstations without harddiscs). The thin clients in two modes: either they use Network Boot server only as a file server and all the applications they run thyself, or they use server also to run applications and perform only as a terminal. In the former case it is possible to use workstations which have todays hardware, i. e. those, which are able to run local operating system after installing a harddisc. The latter solution could reuse behind the times computers. The benefit of this solution is not only the low acquiring cost but also high effectivity of management of such system. The high effectivity of that system is facilitated by the requirement to manage only server and the changes involve also all the workstations.

There is nothing to install on the new workstations. Attachment of the new workstations to that network is easily done by small interference with the server, connecting to the network and turning on the workstation. The amount of management is implied by the hardware used in the workstation. Mainly of its network card and the support of network remote boot on it.

Farm of Thin Clients

The concrete example of such solution is a server P4 2400, 2GB RAM, 2x36 GB SCSI discs in software RAID1 mirror, 66 clients, 20 of them running application on server. The solution with such number of clients is far from its limits. Few days before this farm was working on the server AMD Athlon, 1,5GB RAM, 2x40 GB IDE discs in software RAID1 mirror and resources were not fully utilized also. The users usually run terminal application, e-mail client, internet browser and OpenOffice suite. All users are running the KDE user environment.

Farm with Thin Clients Running Applications on Server

This solution is, compared to previous hybrid one, of lower cost in management, since it is not necessary to hold a copy of the system for clients. But it is more limiting in the number of attached clients. In dependence on number of applications, which users use for their work, it is available to attach only several tenth of clients to the server. Using the clients running applications thyself it is a multiply of clients.