Tag Archives: howto

Hardware

Supermicro Motherboard Front Panel Header JF1

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I’ve had the chance to build a few AMD-based Supermicro boxes over the years. SuperMicro makes server cases, motherboards, and other datacenter equipment. Because they provide both cases and motherboards, they’ve standardized a front panel header that works, I presume, with all of their products. I have only ever used alternative ATX rackmount cases, so I have been left to wire up the front panel headers by hand.

Unfortunately, the pin diagram for the SuperMicro front panel header on some of their boards isn’t what I’ve come to expect building boxes over the years. Most motherboards will declare Signal+ and Signal- for all things that are relevant on the front panel, but the front-panel header on the H11SSL SuperMicro boards looks like this:

The power and reset buttons are labeled as expected, Power+ and a nearby ground. The LEDs however list each LED with an adjacent 3.3V powered pin. Typically I would expect to see LED+ and LED- or LED and ground, so for a while I was avoiding plugging in the LEDs to avoid frying any case panels or motherboard parts.

A short time ago, I looked for pinouts for other SuperMicro boards (since the connector is standard), and I found the explanation. Here’s a description of the C7z97 motherboard header pinout:

This makes it more explicit. Each LED listed is LED- while the 3.3V pins are intended to be LED+.

This article also backs up my findings: https://www.unixgr.com/pinout-for-supermicro-fp836-front-panel-connector/

To switch naming conventions within a diagram seems odd, but now it’s clear. Maybe someone else will find this useful.

Howto

OpenStack Python API Service Catalog

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How do you get an OpenStack service catalog via the Python API? It took me way too long with too much code digging to figure it out, so I’ll share.

Note that the following was tested on versions rocky and stein.

The way that works for anyone that can log into the identity node:

from keystoneauth1 import loading, identity, session, exceptions

auth = identity.Password(
    auth_url,
    username=username,
    password=password,
    user_domain_id="default",
    project_domain_id="default",
    project_name=project_name )
sess = session.Session( auth=auth )

# This step was not obvious. It doesn't seem 
# to be directly doable from the Session, 
# which seems like the more obvious approach.
auth_ref = sess.auth.get_auth_ref(sess)
catalog = auth_ref.service_catalog.get_endpoints( interface="public" )
service_endpoints = {}
for s_name in catalog:
    s = catalog[s_name]
    service_endpoints[s_name] = s[0]["url"]

# Here's a dictionary of service-type -> endpoint URL
service_endpoints

This was actually the second technique discovered. The technique below was the first, but it only works for users that have admin privileges to a project and (I think) reader privileges to the project services.

from keystoneauth1 import loading, identity, session, exceptions
import keystoneclient

auth = identity.Password(
    auth_url,
    username=username,
    password=password,
    user_domain_id="default",
    project_domain_id="default",
    project_name=project_name )
sess = session.Session( auth=auth )

keyclient = keystoneclient.client.Client(
    "3.0",
    session=sess )

service_endpoints = {}
service_list = keyclient.services.list()
for s in service_list:
    endpoints = keyclient.endpoints.list( enabled=True, service=s.id, interface="public" )
    service_endpoints[s.type] = endpoints[0].url

# Here's a dictionary of service-type -> endpoint URL
service_endpoints

Note that the URLs from this technique will not include project ID’s, instead including a token to be replaced: %(tenant_id)

I have opened a question on Ask OpenStack that might eventually result in a better option: https://ask.openstack.org/en/question/123404/how-to-get-service-catalog-with-python-api/#123445

Howto

Ubuntu on Asus Zenbook Flip UX360C

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Notes

  • Model: Asus Zenbook Flip UX360C bought from Microsoft Store – link
  • Software: Ubuntu 16.04.2 LTS Desktop via DVD ISO – link

Getting Started

  1. Power up the Zenbook Flip
  2. On the boot-up screen, push ESC
  3. Select “Enter Setup”
  4. Go to Boot menu
  5. Go to “Add New Boot Option”
  6. “Add Boot Option” -> <pick a name> (I used “USB DVD”)
  7. “Path for boot option” ->
    1. Select the option that isn’t the HD (Mine is “PCI(14|0)\USB(0,0)\CDROM(Entry1)”)
    2. “<efi>”
    3. “<boot>”
    4. “bootx64.efi”
  8. Create
  9. OK
  10. ESC key
  11. “Boot Option #1” -> <the name you chose earlier> (I used “USB DVD”)
  12. Go to Save & Exit menu
  13. “Save Changes and Exit”
  14. Yes
  15. From the boot options, choose “Run Ubuntu” (I could not get a direct install to work)
  16. Run “Install Ubuntu 16.04 LTS” found on the desktop
  17. Choose the installation parameters you prefer. I like:
    1. Pull updates while installing
    2. Leave Secure Boot ON
    3. Encrypt the disk
    4. Encrypt the home drive

Out of Box Problems

Big Ones

  • Some lid-close/open suspend-resume cycles bypass the lock screen entirely. This is a security problem. When this happens, the mouse click doesn’t function. However, pressing the Windows key a couple times seems to restore that.
    Try it for yourself: Open a Terminal, System Settings, and Firefox and go through some suspend-resume cycles.
    They say this is the problem: https://bugs.launchpad.net/ubuntu/+source/gnome-screensaver/+bug/49579
    I’m not entirely convinced.
  • Reboots are a gamble. After the main decryption passphrase, Ubuntu (kernel 4.8.0-41) can stop at an arbitrary point and never continue. Using the advanced Ubuntu options to boot with a different kernel (4.8.0-36) seems to get past this. Unfortunately this isn’t the first time I’ve seen this kind of instability with Ubuntu + Zenbook.
  • The touchscreen can become useless after several suspend-resume cycles. It registers a move of the pointer, but no clicks. I couldn’t find a way to restore this short of a reboot.

Annoyances

    • Lots of complaints of problems on startup: 
      System program problem detected
    • Suspend-resume is generally fragile. After many attempts, I find that I can’t connect to wifi. It claims to see one network, not mine. Cycling the Ubuntu networking off and on doesn’t help. Rebooting worked, but this may also help: 
      $ sudo service network-manager restart

      If I see the problem again, I’ll give it a try.

    • The lock screen after suspend-resume also seems to flake out every once in a while with an odd flicker and/or focus change. The password field should always be focused. One odd manifestation of this was auto-starting a guest session on resume. Another was the absence of a password box, leaving me unable to log back in. 
      $ sudo service lightdm restart

      or a machine restart will get you running again, but you will lose your desktop session.

    • Lid-close suspend-resume can result in windows resizing. This might be related to the above problem.
    • Sequences of opening and closing the lid can leave the laptop active while closed. This isn’t new to this model laptop, but it would be nice if it didn’t happen. This generally results in returning to a dead or near dead battery sometime later.
    • The Windows sticker on the back doesn’t come off clean. It leaves behind a sticky residue that seems to prefer the chassis material. Some soft cotton cloth, rubbing alcohol, and elbow grease will clear it up. Be careful to avoid the Serial Number sticker. That may be helpful to have in the future.
    • The brightness function keys don’t function. This is a pretty common Zenbook issue, but it looks like it may be fixed with the 4.10 kernel (17.04?): https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1348890
      Some workarounds are listed with the bug, but you can use the built-in UI controls, xbacklight, or xdotool.

Preferences

  • Power button asks what to do — on this model it should just suspend. This page has the answer 
    $ gsettings set org.gnome.settings-daemon.plugins.power button-power 'suspend'
  • Suspend when inactive for some time (30 min works for me). I hate returning to a dead battery after getting side-tracked for a few hours. 
    $ gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-battery-type 'suspend'
$ gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-battery-timeout 1800
  • Also, shut down when the battery gets critically low (defaults to 10% battery). A clean shutdown is usually preferable: 
    $ gsettings set org.gnome.settings-daemon.plugins.power critical-battery-action 'shutdown'
  • Lock screen after short period. This is a small usability feature that I like in the event that I see the screensaver kicking on but can’t get to the machine in time to avoid entering a password. It doesn’t need to be long (30 s): 
    $ gsettings set org.gnome.desktop.screensaver lock-delay 'int32 30'

Other Thoughts

Ubuntu on Zenbook hasn’t been the most robust usability combination. Most of the applications work fine. It’s just the edges that could use some polish. The lock screen specifically has been a persistent problem. It looks like it may have gotten worse with this notebook model.

With that said, I prefer having an Open Source option, and Ubuntu seems to be among the best.