---
created: 2024-01-29T05:19:01.392Z
type: topic
updated: 2024-12-05T14:57:36.000Z
---

# Ubuntu

- [Barcode Host](../.kanbn/archive/barcode-host.md)

```bash
uname -a
hostnamectl
lsb_release -a
cat /etc/issue
cat /etc/os-release
```

```bash
sudo -l
timedatectl set-timezone America/Phoenix
find / -name "secrets.json" 2>/dev/null
ls -1 | wc -l
cp -R -u -p /source /destination
```

```bash
cd /home
# directory percent tree
ncdu
ncdu --sort=name-desc
```

```bash
adduser syncthing
```

```bash
# Free space
df -h --total
vgdisplay
lvdisplay
lsblk
apt install smartmontools
smartctl -i /dev/sda
```

```bash
# mount
mount /dev/sda4 /mnt
umount /dev/sda4
# mount -o remount,uid=1000,gid=1000,rw /dev/sda4
# mount -t ntfs -o nls=utf8,umask=0222 /dev/sda4 /mnt
# mount -t ntfs -o ro /dev/sda4 /mnt
# mkdir /home/mike/1-Images-A
# mount --bind /mnt/1-Images-A /home/mike/1-Images-A
# mount -o remount,rw /home/mike/1-Images-A
# umount /home/mike/1-Images-A
# rm -R /home/mike/1-Images-A
mkfs -t ext4 /dev/sda4
mount /dev/sda4 /mnt
blkid
```

```conf
/dev/sda4: UUID="27753635-40b1-4f21-8f6c-28b1c1997cfb" BLOCK_SIZE="4096" TYPE="ext4" PARTLABEL="Basic data partition" PARTUUID="b920a38c-4682-4c16-9abd-a385fd57b29d"
```

```bash
# https://askubuntu.com/questions/45607/how-to-mount-partition-permanently
nano /etc/fstab
```

```conf
/dev/disk/by-uuid/27753635-40b1-4f21-8f6c-28b1c1997cfb /mnt ext4 defaults 0 2
```

```bash
fdisk -l
lvdisplay
lvm lvextend -l +100%FREE /dev/ubuntu-vg/ubuntu-lv
esize2fs -p /dev/mapper/ubuntu--vg-ubuntu--lv
```

```bash
apt-get install lshw
lshw -class disk -class storage
lshw -html > /var/www/html/my-specs.html
nano /var/www/html/my-specs.html
apt-get install smartmontools
smartctl -i /dev/sda
apt-get install hdparm
hdparm -I /dev/sda
```

```bash
# https://stackoverflow.com/questions/338037/how-to-check-permissions-of-a-specific-directory
ls -la
namei -l
getfacl
stat -c "%n %a"
```

```bash
# https://www.cyberciti.biz/faq/how-to-use-sed-to-find-and-replace-text-in-files-in-linux-unix-shell/
sed -i 's/net8.0/net6.0/g' Shared/OI.Metrology.Shared.csproj
```

```bash
# all users
compgen -u
# all groups
compgen -g
usermod -a -G docker mike
groups list mike
```

```bash
# https://stackoverflow.com/questions/49249375/how-to-disable-cloud-init-networking
/etc/cloud/cloud.cfg.d/99-disable-network-config.cfg
```

```yaml
network: {config: disabled}
```

```bash
# https://intercom.help/privatevpn/en/articles/6440374-how-to-disable-ipv6-on-ubuntu-and-fedora-linux
nano /etc/sysctl.conf
```

```conf
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1
```

```bash
sysctl -p
cat /proc/sys/net/ipv6/conf/all/disable_ipv6
```

```bash
# https://www.omgubuntu.co.uk/2021/07/enable-minimize-click-ubuntu-dock
gsettings set org.gnome.shell.extensions.dash-to-dock click-action 'minimize'
```

```bash
# View package virtual IP per Peter Kim
mviewcl
```

```bash
apt list --installed
lsof -i -P -n | grep LISTEN
lsblk -I 8 -o NAME,SIZE,TYPE,FSUSED,FSUSE%
lsblk -b -o NAME,SIZE,TYPE,VENDOR,MODEL,SERIAL
(echo >/dev/tcp/localhost/22) &>/dev/null && echo "Open 22" || echo "Close 22"
```

## Find symbolic links

- [how-to-list-all-symbolic-links-in-a-directory](https://askubuntu.com/questions/522051/how-to-list-all-symbolic-links-in-a-directory)

```bash Wed Jul 31 2024 11:19:12 GMT-0700 (Mountain Standard Time)
find . -type l -ls
find . -type f -maxdepth 1 |  wc -l 
```

## Save and Restore Permissions

- [is-it-possible-to-create-a-script-to-save-and-restore-permissions](https://stackoverflow.com/questions/3450250/is-it-possible-to-create-a-script-to-save-and-restore-permissions)

```bash Wed Jul 31 2024 13:25:41 GMT-0700 (Mountain Standard Time)
getfacl -R yourDirectory > permissions.acl
setfacl --restore=permissions.acl
tree -ap>tree.txt
```

## NVMe Slot Gen

- [how-to-determine-from-command-line-if-nvme-slot-is-gen-3-or-gen-](https://askubuntu.com/questions/1428578/how-to-determine-from-command-line-if-nvme-slot-is-gen-3-or-gen-4#:~:text=Here%20we%20can%20see%20the,generation%20of%20the%20PCIe%20itself.&text=Here%20we%20can%20see%20the%20slot%20supports%20up%20to%2016,s%20thence%20it%20is%20Gen4)

```bash 1731286496058 = 638668832960580000 = Sun Nov 10 2024 17:54:55 GMT-0700 (Mountain Standard Time)
lspci | grep -i nvme
# 02:00.0 Non-Volatile memory controller: Sandisk Corp WD Black SN770 / PC SN740 256GB / PC SN560 (DRAM-less) NVMe SSD (rev 01)
lspci -vv -s 02:00.0 | grep -w LnkCap
# LnkCap: Port #0, Speed 16GT/s, Width x4, ASPM L1, Exit Latency L1 <8us
```