Storage and Networking
Linux on LinuxONE
This course is for Linux Systems Administrators, Architects and Developers who are already familiar with Linux components and everyday tasks, but need a primer on how to best take advantage of the LinuxONE platform. This includes working with the hardware, software, facilities, and processes unique to LinuxONE. It is comprised of videos, links to online resources, and a final test for a badge.
Applying Architecture
Storage and Networking 4:24
Architecture Overview3:20
Installation2:33
Jeff Bisti
IBM Z Ecosystem Architect
Mark Bylok
Global Curriculam Manager
With regards to storage, there are a number of options on LinuxOne. If you're in a shop with IBM Z systems already, you probably have access to direct access storage devices, or DASD, D-A-S-D. LinuxOne can access devices formatted as ECKD, that's extended count key data within those devices. We can also attach NVME SSDs directly to the system, which will show up as PCIe devices to the Linux instance. Or we can use SCSI Sarkozy to access fiber channel attached devices over a storage area network or SAN. These provide a great deal of redundancy and flexibility since we can establish multiple paths between each host port adapter and then lens it's accessing. And once again, under a hypervisor, there are even more ways to slice up storage and present it to the guest operating system. There's also the option of software defined storage in the way of spectrum scale, this allows for a single volume or a collection of volumes to be online to multiple systems at the same time. And this can be incredibly beneficial for images running in tight clusters. When it comes to network connectivity, ethernet is provided by open systems adapters or OSA adapters, O-S-A. That's what gives you links to other systems, other networks, devices, etc. These can be shared between LPARs and they offer a robust and reliable connection to a network. Multiple OSA cards can also be aggregated together in what's known as a link aggregation group. They appear as a single logical link to the system. You've got just one interface to manage on the Linux side. But by grouping them together, we gain bandwidth and increased resiliency. Then we get to HiperSockets. These are one of my favorite things about virtualized resources. When you've got, for example, a database client making requests to a database server, and the database server and the database client reside in separate Linux instances in the same physical system, rather than sending that request out on a wire and through a switch and who knows what else, we can connect them through this microcode emulation of a logical link control layer called a HiperSocket. Now they can communicate at memory speed with nearly zero latency without involving any additional pieces of hardware, they never leave the box. There's no a wire involve. The whole thing is in system. To the Linux system though it's just another network interface that shows up in an Ifconfig, simple as that. If you're coming from the world of multiple racks of stand-alone systems all cabled together, you can start to see how this consolidation has its unique advantages. Typically, when it comes to devices in this architecture, the device has a certain number of Linux addresses which can be brought online to the system. Then there's a Linux driver which is able to see those addresses on the device and make a Linux device out of them. For example, Linux makes use of the QETH driver that's Q-E-T-H, to use the OSA express adapters which get it on the network. Same driver used for the internal HiperSockets we just talked about. If you're working in a system, in an LPAR, it should be planned out ahead of time which devices that LPAR will need access to. For systems running within ZVM or KVM, you'll probably want to use some virtual switch or a Network Address Translation, NAT to handle network traffic. Either way, it all comes back to mapping out the physical resources to the logical resources. You can bet we've included a number of links to get you up to speed on that. There's a few links in there for diving deeper into topics like HiperSockets, link aggregation, OSA express and fiber channel attached storage. Make sure you check those out. In our next section, we'll turn our attention towards the LinuxOnes architecture.