Modding/upgrading Arista switches?

Discussion in 'Networking' started by oddball, May 18, 2018 at 8:24 AM.

  1. oddball

    oddball New Member

    Joined:
    Friday
    Messages:
    6
    Likes Received:
    1
    I've become sort of obsessed about Arista switches. I love that they're a Linux machine with a nice switch OS on top.

    I have a 7050Q-16 that I took apart recently. It uses standard RAM and has a SATA slot on the motherboard.

    Has anyone upgraded the RAM in these things?

    Second has anyone tossed in an industrial flash, or SSD? Something like this (Industrial Disk on Module Kingspec SATA DOM 22Pins 128GB4CH Horizontal+Socket HS | eBay) ?

    I found a doc floating around (https://www.arista.com/docs/Manuals/statement_of_volatility.pdf) that shows the internals for a number of models.

    It looks like the 7124SX might be the most expandable of the platform. It includes a M.2 slot along with a SATA slot as well. The only issue with the 7124SX is the version of EOS it maxes out at. I believe in 4.17 or 4.18 they added the ability to run containers, which if you're modding these is very useful.

    Interested in any experiences.
     
    #1
  2. Patrick

    Patrick Administrator
    Staff Member

    Joined:
    Dec 21, 2010
    Messages:
    10,779
    Likes Received:
    3,760
    I am not this brave, even with the cold spare sitting around.
     
    #2
  3. pcmoore

    pcmoore New Member

    Joined:
    Apr 14, 2018
    Messages:
    7
    Likes Received:
    2
    I had written off Arista switches because I couldn't find an easy way to get easy access to official firmware updates without a support contract. Aside from the hardware tweaks you mentioned above, is it possible to replace the software stack on the device? If so, any pointers you can share?
     
    #3
  4. oddball

    oddball New Member

    Joined:
    Friday
    Messages:
    6
    Likes Received:
    1
    So yes and no.. You can find EOS versions floating around. But for most of us who aren't buying current hardware there is a hard stop on what version is supported.

    If you buy something like a 7050qx-32S you can install Azure's SONIC on it and get updates (it's open source and free).

    But here's another way to look at this. Arista has built in support for guest VM's. Any OS in qemu format can run on the switch. And the switch very rarely hits the OS in forwarding mode. If you are using less than 100% of the ports it's almost impossible for switching to happen in software, not in silicon.

    So you have a switch with a Linux hypervisor. You could even run Windows on these things. The biggest limitation is really the small storage and RAM that come out of the box.
     
    #4
    pcmoore likes this.
  5. pcmoore

    pcmoore New Member

    Joined:
    Apr 14, 2018
    Messages:
    7
    Likes Received:
    2
    Thanks for the info. I wasn't aware of the work Microsoft/Azure was doing with SONiC on real hardware; I knew they had a software switch, but I didn't realize it could run on proper switching hardware. The VM-on-a-switch is less interesting to me, but I realize that is a fairly unique capability that will appeal to a lot of people.

    I might have to look into this if I ever find a deal on one of the supported switches. I just managed to score a Dell 8024 and 8132/N4032 pretty cheap this week, but it looks like neither are supported :/
     
    #5
  6. oddball

    oddball New Member

    Joined:
    Friday
    Messages:
    6
    Likes Received:
    1
    Yeah, Sonic is interesting but it’s only supported on newer models.

    I find the VM thing fascinating. We have two of these in production and I’m trying to snag a few to hack on. Specifically to run souped up specific purpose VM’s right on the switch.

    My though is to a VM this is essentially a small server with a ton of NIC’s. I want to try running some IDS stuff right on the switch. Or alternatively this could be an interesting router/firewall device.

    There are some really interesting applications with a VM and tap aggregation. The limiter in most of this is storage and RAM.
     
    #6
  7. pcmoore

    pcmoore New Member

    Joined:
    Apr 14, 2018
    Messages:
    7
    Likes Received:
    2
    I wonder about the ability of the VM's CPU(s) to process the packet stream for more than a handful of ports at full line rate. While the switching fabric can obviously handle it, I have a hunch that the CPU's I/O interface can't handle a full load and I'm almost certain that the CPU itself couldn't process a full compliment of ports running at line rate. Perhaps Arista has some special sauce to make it possible, or at least filter traffic hitting the VMs.

    I'm very curious to hear more about your experiments with packet processing in the VMs once you've had some time to play.
     
    #7
  8. oddball

    oddball New Member

    Joined:
    Friday
    Messages:
    6
    Likes Received:
    1
    I found a paper discussing running the Bro IDS on an Arista switch. They had it setup where the VM read the events and offloaded to collectors on compute nodes. With a few nodes they were able to process 50Gbps real-time. They said the limitation to getting to 100Gbps wasn't the switch, but the collector nodes.

    Now granted this isn't 1Tbps, or whatever these boxes can do, but it was impressive. The idea was to put an IDS like this on the ingress ports.

    Another interesting application is running HAProxy right on the switch to do load balancing and fail-over.

    I have a 7124SX arriving Thursday that I'll use to test this stuff. I am going to upgrade the flash to 16GB or 32GB, and toss in an SSD and more RAM. Goal is to get the thing fired up like that, then work on VM's.

    In newer versions of EOS they natively support Docker. But since this is just Fedora I don't see why I can't install Docker myself and run containers on here.

    Performance will be interesting. I'll keep the thread updated.
     
    #8
Similar Threads: Modding/upgrading Arista
Forum Title Date
Networking Emerson Power Supply vs. Arista Emerson Power Supply May 3, 2018
Networking Arista 7050S - 100mbit through rj45-sfp? Feb 6, 2018
Networking Dell Mellanox connectx-3 to Arista 7050, no link? Jan 18, 2018
Networking Upgrade Flash Storage on Arista 7050QX-32 Jan 1, 2018
Networking Roll back SONiC to EOS on Arista 7050QX-32 Dec 29, 2017

Share This Page