Create a New User

Open the root user terminal and run the following command:

# adduser username

Add a user to the sudoers file

# usermod -a -G sudo rogerp

Add with visudo

Login as root.

Run

# visudo

Add the user with:

username      ALL=(ALL:ALL) ALL

Save file.

Ready to Go!

Run sudo /usr/bin/nvidia-uninstall to uninstall a manually installed driver, if you still got one.

Remove everything of your old NVIDIA driver (simulate first):

<code>sudo apt remove --purge -s nvidia-*
sudo apt remove --purge -s libnvidia-*
</code>

If only nvidia packages are there to be removed, remove really:

<code>sudo apt remove --purge nvidia-*
sudo apt remove --purge libnvidia-*
</code>

Run sudo apt update and ubuntu-drivers devices again.

If nvidia-390 is still recommended, add your output of sudo ubuntu-drivers autoinstall again.

Great Article: https://www.digitalocean.com/community/tutorials/how-to-install-jitsi-meet-on-ubuntu-18-04

Best Article: https://www.atlantic.net/hipaa-compliant-hosting/how-to-install-openfire-ubuntu-20-04/

The original installation of zpool was from a POPOS 20 install. After Installing a new Ubuntu system over the top of POPOS, the zpool was not listed. Here are the steps to restore the zpool.

Install zfsutils

# apt install zfsutils-linux

When trying to import, I received an error:

# zpool import
   pool: myzpool
     id: 13464327419314907931
  state: ONLINE
status: The pool was last accessed by another system.
 action: The pool can be imported using its name or numeric identifier and
	the '-f' flag.
   see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-EY
 config:

	myzpool                                         ONLINE
	  mirror-0                                      ONLINE
	    ata-WDC_WD2002FFSX-68PF8N0_WD-WCC6N7PRY8JJ  ONLINE
	    ata-WDC_WD2002FFSX-68PF8N0_WD-WCC6N7PRY1VJ  ONLINE
root@skynet:/home/rogerp# zpool import myzpool
cannot import 'myzpool': pool was previously in use from another system.
Last accessed by pop-os (hostid=b5f0b0a0) at Tue May  4 04:27:02 2021
The pool can be imported, use 'zpool import -f' to import the pool.

Import using the -f flag and the pool name that was created originally.

# zpool import -f myzpool

Resources:

https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-EY/

How to mount a NTFS disk in Debian.

Find the disk:

# fdisk -l
Disk /dev/sda: 232.9 GiB, 250059350016 bytes, 488397168 sectors
Disk model: ST3250310AS
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x84c02518

Device     Boot     Start       End   Sectors  Size Id Type
/dev/sda1  *         2048 471801855 471799808  225G 83 Linux
/dev/sda2       471803902 488396799  16592898  7.9G  5 Extended
/dev/sda5       471803904 488396799  16592896  7.9G 82 Linux swap / Solaris


Disk /dev/sdb: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Disk model: WDC WD10EZRX-00L
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x93665d93

Device     Boot Start        End    Sectors   Size Id Type
/dev/sdb1        2048 1953521663 1953519616 931.5G  7 HPFS/NTFS/exFAT

So, the NTFS is disk sdb1. Find the UUID value.

 sudo blkid  /dev/sdb1
/dev/sdb1: LABEL="Backup" UUID="0CF88F39F88F2056" TYPE="ntfs" PTTYPE="atari" PARTUUID="93665d93-01"

Install NTSF-3G:

# sudo apt-get install ntfs-3g

Create the /mnt/ntfs/ directory

# sudo mkdir -p /mnt/ntfs/

Add to fstab.

# nano /etc/fstab
# UUID="YOUR-UID-HERE" /mnt/ntfs/ ntfs-3g rw,uid=1000,gid=1000,dmask=0002,fmask=0003 0 0
UUID="0CF88F39F88F2056" /mnt/ntfs/ ntfs-3g rw,uid=1000,gid=1000,dmask=0002,fmask=0003 0 0

Test it

# sudo mount -a

# df -h
/dev/sdb1       932G  295G  638G  32% /mnt/ntfs

# cd /mnt/ntfs/
# ls -l

Some great scripts for stress testing and benchmark tests:

https://haydenjames.io/linux-benchmark-scripts-tools/

CentOS

For CentOS, the DIG tool is a part of the BIND Utilities so you need to install them.

# yum whatprovides '*bin/dig'

To install the BIND Utilities, type the following:

# yum install bind-utils

Debian

Update Debian

 $ sudo apt update

Install dnsutils package with the following command:

$ sudo apt install dnsutils -y

Check dig

dig -v
DiG 9.11.5-P4-5.1+deb10u5-Debian

To find out where disk space is being used:

Get to the root of your machine by running

# cd /

Run

# sudo du -h --max-depth=1

Note which directories are using a lot of disk space.
cd into one of the big directories.
Run

# ls -l

to see which files are using a lot of space. Delete any you don’t need.
Repeat steps to run once you cd into the directory with the largest size

sudo du -h --max-depth=1