Olivier Hault sent me an interesting challenge:
I cannot find any simple network-layer solution that would allow me to use total available bandwidth between a Hypervisor with multiple uplinks and a Network Attached Storage (NAS) box.
TL&DR summary: you cannot find it because there’s none.
Read more ...TL-DR: This week I'm started a magazine style newsletter called "Pieces of Human Infrastructure". You can sign up at http://etherealmind.com/pieces-human-infrastructure-newsletter/
The post Announcing: Pieces of Human Infrastructure Magazine appeared first on EtherealMind.
Who doesn’t like automation? If you’re speaking to somebody in IT, then the short answer is “nobody”.
While the term Zero Touch Provisioning (ZTP) might be increasingly more common to networking, the concept of automation has existed for years in IT. At its core, ZTP is an automation solution that’s designed to reduce errors and save time when an IT administrator needs to bring new infrastructure online.
This is particularly useful for data center servers, where scale and configuration similarities across systems make automation a necessity. In the server world, the Linux-based operating system has revolutionized on boarding and provisioning. Rather than using command-line interfaces (CLI) to configure these systems one at a time, administrators can use automation tools to roll out the operating system software, patches, and packages on new servers with a single command, or the click of a mouse.
Advanced scripting capabilities also allow administrators to tailor the boot configuration of these systems with profiles for specific applications. So for example, if you need ten servers for a new Hadoop cluster, you can load this with one profile, but if you need six new servers for a new web application, you can Continue reading
Having large amount of subnets (and other tables) on unoptimised MySQL database server can significantly increase page loads. To see which parameters need to be change I usually use mysqltuner perl script, which connects to database, analyses data and proposes which parameters need to be changed that are not optimally set based on current load.
Installation is simple:
1.) Fetch mysqltuner on FreeBSD:
cd ~ fetch http://mysqltuner.pl
or wget on linux:
wget http://mysqltuner.com
2.) Make it executable:
chmod +x mysqltuner.pl
3.) And run it to analyse database, you have to provide administrative credentials.
./mysqltuner.pl
Any other similar scripts out there you would recommend?
brm
I just saw the news that Citrix has acquired Sanbolic, a storage virtualization company that I’ve written about before. (TechCrunch also has a quick write-up as well.) Early this year, Sanbolic announced their storage virtualization product, completing a pivot from offering a Windows-only solution (file system and volume manager) to a multi-platform solution that encompasses multiple storage tiers, multiple operating systems, and multiple hypervisors.
It will be interesting to see how this acquisition affects the virtualization industry. With the exception of a few major players running open source Xen, Citrix has thus far been unsuccessful (to my knowledge, correct me if I’m wrong) in making any significant inroads with XenServer (either commercial or open source). KVM seems to be the open source hypervisor of choice while VMware’s vSphere continues to dominate (for now) the commercial market—leaving XenServer with leftovers. The same can be said for CloudStack, which—with a few exceptions—is losing to OpenStack on the open source side and VMware’s offerings on the commercial side.
So the big question becomes, “Will the Sanbolic acquisition change things?” Will the addition of a storage virtualization solution that supports multiple operating systems and multiple hypervisors give Citrix an edge that Continue reading
Much of our life, as engineers, is about building, manipulating, and using abstractions. For instance, C is nothing but an abstraction on top of the actual register set provided by a particular processor. HTML is nothing but an abstraction for formatting and display (a markup language), implemented in — well, C. There is a lot of power in such abstractions, of course. Without them we couldn’t build operating systems, applications, browsers, web pages — or networks.
Ethernet is an abstraction of electronic signals (anyone remember Manchester Encoding?). IP is an abstraction of every physical layer in the world. TCP is an simulation, or abstraction, of a reliable connection oriented link over (completely unreliable) IP. HTTP is an abstraction of a flow of information, a stream, between two computers. It’s all abstractions — as the philosopher might say, “it’s abstractions all the way down.” So what’s wrong with this?
All abstractions are leaky. What do I mean when I say abstractions are leaky? Let’s turn to the originator of the phrase, Joel Spolsky:
Abstractions fail. Sometimes a little, sometimes a lot. There’s leakage. Things go wrong. It happens all over the place when you have abstractions.
This is the Continue reading
This sponsored podcast is a continuation of our series recorded at HP Discover Barcelona 2014. Our thanks to Chris Young for organizing the topics and guests. The interesting conversations in Barcelona at HP Discover 2014 continued with a chat about the shifty meaning of “open.” In the world of technology, being open means a lot of different […]
The post PQ Show 41 – HP Networking’s Sarwar Raza on the Meaning of Open appeared first on Packet Pushers Podcast and was written by Ethan Banks.
This is the final post in my series on BGPSEC — I will probably follow this up, at some point, with a couple of posts on some alternatives to BGPSEC, and the larger issue of the evolution of BGP. Basic Operation Protections Offered Replays, Timers, and Performance Signatures and Performance In this final post, I […]
The post BGPSEC: Leaks and Leaks appeared first on Packet Pushers Podcast and was written by Russ White.
What’s the difference between network programmability and SDN? Matt Oswalt explained his view on the topic in the Network Programmability 101 webinar.
Netlink is a Linux Kernel interface that is used to talk Networking between Kernel processes, or from userland to Kernel processes. This post documents how I tamed Netlink and make working with it in Golang easier.
If you want to create an interface, set an MTU, set an IP address …
Netlink is a Linux Kernel interface that is used to talk Networking between Kernel processes, or from userland to Kernel processes. This post documents how I tamed Netlink and make working with it in Golang easier.
If you want to create an interface, set an MTU, set an IP address etc... on a Linux machine then you have to talk Netlink to do it. For Golang, there are a number of libraries, but this one seems to be gaining a lot of traction recently. Honorable mentions go to Tenus and Docker's libcontainer.
Now, this library is good, but it isn't complete and some of the behavior I need is missing. So how does one go about implementing it you might ask?
Here's my process:
iproute2 source codeThe iproute2 utility is insanely useful - it replaces ifconfig and route for those with memories long enough.
In my case, the feature I wanted was here and I could take a look at the exact message structure required :)
Once I'd written my tests and code, I wasn't surprised to see that things were not working.
strace will get you part of the way, but it's Continue reading
Netlink is a Linux Kernel interface that is used to talk Networking between Kernel processes, or from userland to Kernel processes. This post documents how I tamed Netlink and make working with it in Golang easier.
This post describes how load sharing and faster convergence in MPLS VPNs is possible by using an unique RD per VRF per PE. It assumes you are already familiar with MPLS but here is a quick recap.
The Route Distinguisher (RD) is used in MPLS VPNs to create unique routes. With IPv4, an IP address is 32 bits long but several customers may and probably will use the same networks. If CustomerA uses 10.0.0.0/24 and CustomerX also uses 10.0.0.0/24, we must in some way make this route unique to transport it over MPBGP. The RD does exactly this by prepending a 64 bit value and together with the IPv4 address, creating a 96-bit VPNv4 prefix. This is all the RD does, it has nothing to do with the VPN in itself. It is common to create RD consisting of AS_number:VPN_identifier so that a VPN has the same RD on all PEs where it exists.
The Route Target (RT) is what defines the VPN, which routes are imported to the VPN and the topology of the VPN. These are extended communities that are tagged on to the BGP Update and transported over MPBGP.
MPLS uses Continue reading
As some of my readers know, I’ve done a fair bit of bike touring. Two of the challenges of bike touring are riding uphill, and riding into headwinds.
Riding uphill is tough. 2,300m passes in snow, or 3,200m passes in sunshine, it’s tough going. But you put your head down, and keep turning the pedals, because you know that eventually you will reach the top, and there will be a downhill reward.
Riding into headwinds is a different story. You can battle into headwinds for days, and never get any reward. It saps your energy, and you don’t know if or when it will ever end. The wind could just keep coming from that direction. I’ve gone to different countries just to avoid the wind in the past.
They’re both hard. But one of them has an end, and a reward. The other one can just keep on sucking away your will to live.
This applies to the rest of your life. The tricky bit is that sometimes you don’t know if you’re going uphill, or into the wind. Both of them feel hard, and you can’t always see the end in sight.