Checking ashift on existing pools

Today I found: Checking ashift on existing pools. In summary:

# zpool get all | grep ashift
# zpool get all | less
# zdb -C | grep ashift
# zdb -C | less
# zdb -U /etc/zfs/zpool.cache | less

Per ZFS 101—Understanding ZFS storage and performance you *really* want to make sure your ashift value is aligned with your disk’s sector size. ashift=9 for 512; ashift=12 for 4096; I’ve heard some SSDs can be 8K, but I haven’t been able to confirm for my own disks.

How to check which process is causing IO wait

The ‘wa’ state in `top` can indicate an IO wait, but to figure out what’s causing the IO wait try this command:

# ps aux | awk '$8 ~ /D/  { print $0 }' | less

You can read more here. Thanks to bsandro on #lobsters.
According to `man top`:

The status of the task can be one of:
  D = uninterruptible sleep
  I = idle
  R = running
  S = sleeping
  T = stopped by job control signal
  t = stopped by debugger during trace
  Z = zombie

Install Docker Engine on Ubuntu

Reading about how to Install Docker Engine on Ubuntu. I suppose it’s about time.

-------------------
Thu Nov 11 20:38:18 [bash:5.0.17 jobs:0 error:0]
root@tact:/home/jj5
# docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
2db29710123e: Pull complete
Digest: sha256:cc15c5b292d8525effc0f89cb299f1804f3a725c8d05e158653a563f15e4f685
Status: Downloaded newer image for hello-world:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (amd64)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://hub.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/get-started/

InfoWorld articles

Today I discovered InfoWorld with these articles:

And a bonus article from Spotify: How We Use Golden Paths to Solve Fragmentation in Our Software Ecosystem .
Also, I should note, I very much like the InfoWorld URL format: https://www.infoworld.com/article/3614850/no-one-wants-to-manage-kubernetes-anymore.html — this is the same URL structure I use in my own designs.