Open Source Tech

Disable Multipath for Identical NVMe Drives on Ubuntu Server

I have 4 identical NVMe drives installed in my system.

Ubuntu treats them as one “multipath” device by default. This is not accurate.

I posted something on Ubuntu Forums, but no response at time of writing. (2021-02-18)

Here’s the problem:

 nvme0n1                   259:0    0   1.9T  0 disk  
 └─mpatha                  253:1    0   1.9T  0 mpath 
 nvme1n1                   259:1    0   1.9T  0 disk  
 └─mpatha                  253:1    0   1.9T  0 mpath 
 nvme2n1                   259:2    0   1.9T  0 disk  
 └─mpatha                  253:1    0   1.9T  0 mpath 
 nvme3n1                   259:3    0   1.9T  0 disk  
 └─mpatha                  253:1    0   1.9T  0 mpath 

The fix is relatively simple. It is outlined in some SUSE Documentation.


blacklist {
       devnode "^nvme[0-9]"

Once the config file has been changed, apply the changes according to the Ubuntu Server Documentation.

sudo systemctl restart multipathd

And all is good!

 nvme0n1                   259:0    0   1.9T  0 disk 
 nvme1n1                   259:1    0   1.9T  0 disk 
 nvme2n1                   259:2    0   1.9T  0 disk 
 nvme3n1                   259:3    0   1.9T  0 disk 

Beef Shoulder Roast

Beef shoulder roast and beef chuck roast were on sale at Harris Teeter.

The sticker on the shoulder roast package said “oven roast” and the one on the chuck roast package said “pot roast”.

I put the shoulder roast in the oven. It worked out well.

It tastes like the beef that comes in a Chinese restaurant dish. It is relatively tough and relatively lean. Has good strong flavor. Would definitely make again.

It was delicious cut up into strips to make a sandwich!



I tried making hamburgers today. The result tasted like bland meatloaf.

I’ll try again later this week.


How Bloated is Windows 10?

Despite the click-bait header, I will not comment on whether the size of a Windows installation is “too” big.

However, I do have facts!

I installed Windows 10 version 20H2 on a VM with no internet connection.

Once I was on the home/welcome/desktop screen, the installation used 18.8 GiB.

After performing Windows updates, and installing VirtIO drivers (to help performance of VM) the total install size was 23.5 GiB.

These results were logged on 2021-02-07.

Open Source Tech

Fail: USB Passthrough to Dexcom 6 Reciver

My T1 Diabetic Connundrum

I want to connect my Dexcom receiver to a computer. This will allow me to track my blood glucose over time. Then, I can identify trends and patters to help improve my insulin dosing.

Mac and Linux

Dexcom’s software only appears to work for Windows. I only have Mac/Linux/FreeBSD machines at home. I want to pass the USB Dexcom device through to a Windows VM.

Proxmox USB Passthrough: Success

For many people and use cases, this seems to work fine!

I was able to pass a USB flash drive through to a Windows VM with no issue.

Proxmox USB Passthough: Fail

Things were looking promising after the USB flash drive worked!

They looked even more promising after the Qemu Monitor recognized the Dexcom device.

qm> info usbhost
   Bus 1, Addr 15, Port 10, Speed 12 Mb/s
     Class 02: USB device 22a3:0047, DexCom Gen4 USB Serial

Unfortunately, the device was not recognized by the Windows Device Manager.

I thought this might be fine, and that the Dexcom software would find the right driver and solve the problem! However, the Dexcom program gave prompts as if the device was not plugged in.


Proxmox has robust documentation on USB passthrough on their wiki.

The basic things I tried were

  • Physically unplug and re-plug the device
  • Drop/Add the Qemu USB device using USB bus/port numbers
  • Drop/Add the Qemu USB device using Vendor and Product IDs

Sample Commands:

#device info
 qm> info usbhost
   Bus 1, Addr 15, Port 10, Speed 12 Mb/s
     Class 02: USB device 22a3:0047, DexCom Gen4 USB Serial
#by bus and port
 device_add usb-host,hostbus=1,hostport=10,id=usb1
 device_del usb1

#by vendor and product ID
 device_add usb-host,vendorid=0x22a3,productid=0x0047,id=usb1
 device_del usb1

I tried in different USB ports, after restarting VM, and other miscellaneous troubleshooting as well.

The results were consistently the same failure.


I borrowed a Windows laptop, and it worked fine!

I’m not sure what the root cause is for this issue. One possibility is that the Vendor ID seems to be in USB device databases on the web, but the product ID is not.

It is possible that Proxmox needs to have a valid/known product ID to pass to the VM.

It is also possible that the Dexcom software is written in a way that just doesn’t work when the USB device is not on the bare-metal machine. After all, the VM does need a virtualized USB hub etc., so it might just inevitably break some code.

Another possibility is that the Windows OS layer isn’t pulling the device details through properly, even though Proxmox is sending all it can.

Who knows! With such a tall software stack, combined with a tiny user base (type 1 diabetics with this particular device who are tech nerds like me) the answer to this question is likely to remain a mystery forever. Oh well.

First Times Food

First Ever Rib Roast

I’ve never baked a beef rib roast before! Here’s the story of what happened.

Seasoned it with salt, pepper and garlic. Placed on countertop for a few hours. Put into the oven when the roast was 52 degrees.

Baked at 250 degrees for about 3 hours. Once the roast reached 120 degrees, cranked the oven up to high for almost 10 minutes to get a sear.

After searing and removing from the oven, the roast was at around 126 degrees.

The result was pretty good! I was going for medium rare, but ended up at a medium.

For my first-ever attempt: I’ll take it! ????

Next time I’ll endeavor to have it closer to rare. Stay tuned.

Open Source Tech

Bulk Resize Images for WordPress

Here’s a python script.

import os
import subprocess

# inspired by this post

def main():
    # the maximum length in any direction (width or height)
    # setting at 1600 because full HD (1920x1080) seems larger than necessary
    # this will allow 1600x900 (or portrait 900x1600) images.
    MAX_LEN = "1600" 
    size_parm = MAX_LEN+'x'+MAX_LEN+'>' #
    # files in the input directory will (at least SHOULD) remain untouched.
    # files with identical names will be created in the output directory.
    # files in the output directory are OVERWRITTEN (if they already exist and the names match)
    IN_DIR = '/home/vince/Pictures/WordPress'
    OUT_DIR = '/home/vince/Pictures/WordPressSmall'

    # show what is about to happen
    print ('Input: ', IN_DIR)
    print ('Output:', OUT_DIR)
    print ('Resize Geometry:', size_parm)

    for filename in os.listdir(IN_DIR):
        # get full file paths
        infile =  os.path.join(IN_DIR, filename)
        outfile = os.path.join(OUT_DIR, filename)

        # this is not necessary because the ImageMagick library supports shrinking only
        # AND maintaining aspect ratio. all the logic is basically done.
        # the '>' in size_parm prevents making the image larger.
        # #get width and height
        # width = subprocess.check_output(['identify', '-format', '%w', filepath])
        # width = int(width.decode())

        # convert and print output
        subprocess.check_output(['convert', infile, '-verbose', '-resize', size_parm, outfile])

if __name__ == '__main__':


Observing Jupiter and Saturn Together

Today, Jupiter and Saturn formed a visible “double planet” for the first time in 800 years. It was also the winter solstice.

The winter solstice of 2020 was a once in a lifetime opportunity to see the planets align!

Bethany and I managed to snap a few photos!

Here is the “double planet” that looks like a single one with the naked eye.

Jupiter and Saturn are the bright spot toward the top left of the tree.

With the binoculars, you can see the two planets distinctly. It took both of us together holding the phone camera and binoculars to make this happen ????


Panda Bear is in the Sink

What a great relaxation spot!

Let’s hope she stays out of the toilet!

Open Source Tech

Torrent Container for Proxmox

Why Do This?

I always end up downloading ISO images for use in VMs using my laptop. I’m rarely running the torrent program on my laptop, so I am a leecher!

Proxmox is running 24/7, so I can help the rest of the community by being a seeder!

Creating a container to avoid having too much configuration on the Proxmox server itself. The idea is to keep Proxmox a pure VM host, not a Torrent server.

Plus, the setup is finicky, so being able repeatedly wipe the container and start over is helpful!

Before We Begin

The setup assumes that networking has been configured for both the Proxmox host, and the container that will run the Transmission torrent client.

In case local DNS is not configured, IP addresses are fine!

  • pve1: Physical server that is running Proxmox
  • torrent0: Debian container to run Transmission and Samba.

Both of these servers have IP addresses on the network.

Transmission (Torrent)

root@torrent0:~# apt install transmission-daemon transmission-cli
root@torrent0:~# cp /etc/transmission-daemon/settings.json /etc/transmission-daemon/settings.json.original

root@torrent0:~# service transmission-daemon stop

root@torrent0:~# nano /etc/transmission-daemon/settings.json
    "download-dir": "/srv/smb/template/iso",
    "rpc-password": "YourSecretPassword",
    "rpc-whitelist": "192.168.27.*",

root@torrent0:~# service transmission-daemon start

Downloading a torrent will cause that that directory to be automatically created if it doesn’t exist. Avoid doing that until we’ve completed more steps in the setup.

For more information, see Debian’s documentation.

Samba (CIFS / SMB)

root@torrent0:~# apt install samba

root@torrent0:~# smbpasswd -a debian-transmission
root@torrent0:~# mkdir /srv/smb
root@torrent0:~# chown debian-transmission:debian-transmission /srv/smb/

root@torrent0:/etc/samba# cp smb.conf smb.conf.default 
root@torrent0:/etc/samba# nano smb.conf

   comment = SMB Share 
   path = /srv/smb 
   guest ok = no
   browseable = yes
   readonly = no

root@torrent0:~# systemctl restart smbd
root@torrent0:~# systemctl status smbd

For more information, see Debian’s documentation.

Connect Proxmox

I had buggy issues removing/editing CIFS shares from the web GUI. Falling back to command line.

root@pve1:~# pvesm add cifs tor0 --server torrent0.vnet --share smb --username debian-transmission --password 'YourSecretPassword'
--then manually edited to change storage type to ISO in GUI

This automatically creates /template/iso/ under whatever share you give it.

For more information, see the Proxmox Storage Documentation

And also, forum post related to bugs adding/removing CIFS.

Download ISO Files

The Web GUI can be accessed here: http://torrent0:9091

  • Default UN: transmission
  • PW: Configured earlier in tutorial

I’ve had better luck with .torrent files than magnet links, but YMMV.