To maximize ease of deployment of OpenSCADA you can use live builds of CD, DVD and USB boot disks from Automation Linux distributive of the project OpenSCADA. A live disk provides the ability to download directly from it, and quickly get the desired working environment. When downloaded and running, the live disk does not use regular media, that is, you can not worry about the integrity and consistency of data on them. In general, a live disk is a convenient tool with a wide range of necessary software tools at hand and independent from the stationary software environment capable of implementing:
The live disk is a packed operating system image and applications size of about 700 MB, written to a CD/DVD disk or USB flash storage. In its work, the operating system "on the fly" unpacks the necessary files to run programs and open documents, ie — does not use more RAM than with its stationary installing.
Live disks from Automation Linux distributive of the project OpenSCADA are built in several versions based on Linux distributions Debian, ALTLinux (old versions) and available for download, in the latest version of OpenSCADA, here: http://oscada.org/en/main/download/. Existing live builds from OpenSCADA have much more features than expected from the beginning:
Currently, hybrid ISO images of "the live disks" (*LiveCD_USB.iso) are built mostly, which can be written directly to CD/DVD, USB-Flash, and also extract the contents for recording on USB-Flash with the FAT or EXT file systems.
The main option for creating a "live disk" is the recording on a CD/DVD, which allows you to use the standard tools of the original operating system. Additional, though in fact, already the main one, is the write to USB-Flash, which can be carried out from the environment of the Linux operating system, for example, from the environment of the same "live disk", recorded and downloaded earlier from a CD/DVD; or from the MS Windows operating system via Win32DiskImager.
Writing a "live disk" image on USB-Flash will erase all data and make it unusable for use as a data storage unless you take into account the ability to write to a partition of the changes saving of the environment of the OS live disk that will be created when first downloaded from the live disk, in case ALTLinux, or user in the case of Debian.
The address of the disk to write the ISO-image is "/dev/sd{x}" and you can found it by calling the dmesg console command immediately after connecting the target USB-Flash disk. From the Linux environment, an ISO-image can be written as follows:
# Recording an ISO-image to USB-Flash:
dd if=Debian_9-OpenSCADA_0.9.0-TDE_R14-amd64-LiveCD_USB.iso of=/dev/sd{x} bs=4096
# Recording an ISO-image directly from the loaded CD/DVD live disk:
dd if=/dev/sr0 of=/dev/sd{x} bs=4096
Earlier, separate builds of images were made for recording them on the FAT file system. Currently, these images are specially built only for FirmWare of a number of PLCs (*flash.tar). You can use the hybrid ISO-images described in the section above to create live USB flash disks of general purpose.
The advantage of the live disk on USB-Flash, as it was previously mentioned, is a combination of USB-Flash drive features as a data storage and as a live disc at the same time. Also on the basis you can create compact, reliable and functional solutions of the embedded systems based on OpenSCADA, such as Programmable Logic Controllers (PLC), the panel controllers (with a touch screen), as well as simple SCADA-servers and operator "quickly made" SCADA-stations, by recording a live disk to the stationary data storage (HDD, SSD or Flash). The reliability of this solution is achieved by placing the main non-modifiable software in the packed file, and operational data on the journaled file system.
You can write "live disk" data to a file system from any OS (for FAT), but install the boot loader only on the Linux operating system, for which you can use a live CD/DVD disk from the previous section.
The procedure for creating a live disk is the following, for the data of the hybrid ISO (Debian and ALTLinux):
For a "live disk" image on FAT (ALTLinux), everything from superuser: su -
This method of the live disk deploying requires knowledge of Linux and the command line interface (console), as well as the basics of the disks partitioning because with an wrong initial partitioning of media the booting may not be passed.
The Live disk, as mentioned early, allow you full-featured work with saving the working data, and also updating the programs (excluding the system programs and the OS Linux kernel). Typically that possibility has sense only for USB, HDD, SSD storage.
In the case of Debian distributions, a separate section for storing work data, with the label "persistence", should always be created specially, and in the file "persistence.conf" on it also specify the file system or part of it to be reflected on the record (for example, "/home"). To reflect the entire root file system, you must write "/ union" in the file. As the file system of this partition, it is better to use "EXT4/3". To create a partition you can use the program partition manager, for example — gparted.
ROOT is accessed here through sudo and password for the user set to "live".
In the case of the ALTLinux (6) distribution, and the direct recording of the hybrid ISO image, such a section will be created at first startup. When creating a live disk on FAT and EXT, you need to create a separate partition labelled "alt-live-storage" and the file system "EXT3" that can be done in the partition manager program, for example — gparted.
ROOT is accessed whether through sudo or su and there is no password.
To boot from the resulting "live disk" you need to reboot the computer and at the very start of loading to the stationary OS press the key to enter the BIOS boot menu and select our media (fig. 1). On different computers, the enter key to the boot menu may differ and be one of the following: "F8", "F9", "F10", "F11" or "F12". On some computers you can only change the boot order in the BIOS itself.
After selecting the device, you should see the boot menu for the live disk (Fig. 2) where you can pre-select the boot option in a specific language, for Debian, or your language, with the F2 key for ALTLinux.
As a result of booting a live disk, you will get the TDE desktop (Fig. 3).
| Documents/How_to/Live_disk/en - GFDL | May 2024 | OpenSCADA 0.9.7 |