fstab – Block device management

I searched for this in the forums, and did not find anything that could help me, if this was already discussed please forgive me.
So I have 2 problems/questions:

  1. I recently installed unbuntu server 20.04 and customized the volume group and lv’s, and when I do a simple “df -hP”, I am puzzled to find that one block is shown by ID, and all others by name:

root@ubuntutemplate:~# df -hP |grep -E “home|usr|var”
5.0G 2.2G 2.9G 43% /usr
/dev/mapper/vg_ubuntu-lv_home 5.0G 68M 5.0G 2% /home
/dev/mapper/vg_ubuntu-lv_var 8.0G 1.3G 6.8G 16% /var

As you can see usr filesystem is mounted by id and all others by name. Fstab is configured the same way for all the filesystems.
What controls this behavior and how can I make it same for all?

  1. I renamed volume group “ubuntu–vg” to another “vg_ubuntu”

Noticed that udev rules are still referring to old vg name (I already updated grub and initramfs)

root@ubuntutemplate:/etc/udev/rules.d# ll ubuntu–vg-lv_var.rules
-rw-r–r– 1 root root 140 Feb 17 11:46 ubuntu–vg-lv_var.rules
root@ubuntutemplate:/etc/udev/rules.d# cat ubuntu–vg-lv_var.rules
# Written by curtin
SUBSYSTEM==”block”, ACTION==”add|change”, ENV{DM_NAME}==”ubuntu–vg-lv_var”, SYMLINK+=”disk/by->dname/ubuntu–vg-lv_var”

Is this problematic? Everytime I decide to change a vg is this going to happen? Is there anyway to
automatically update all rules for all block devices (lvs)? Shall I change it by hand?
Thank you very much for the support in this


boot – Gave up waiting for root file system device

Here’s what it says when i first turn on my computer. “BusyBox v1.30.1 (Debian 1 :1.30.1-4) built-in shell (ash)
Enter ‘help’ for a list of built-in commands.
I watched a youtube video expecting it to work but instead when i used exit this is what pulled up.
Gave up waiting for root file system device. Common problems:

  • Boot args (cat /proc/cmdline)
  • Check rootdelay= (did the system wait long enough?)
  • Missing modules (cat /proc/modules; ls /dev)
    ALERT! UUID=d63751a9-a3cc-46c7-99ee-1d6f0abcfede does not exist. Dropping to a shell!

Does anybody have any tips or can anyone walk me through the problems please? Is it unfixable or not

visual studio – How can I make a program to detect a certain USB device and, for example, execute a program?

I want to make a program to execute a program (Gaomon driver) when I connect my Gaomon Tablet to my PC, and before you tell me that it can start with the PC, I don’t want that, I want my PC to start quickly and to do that I’m disabling some programs in the start menu

In short, I want the program to start ONLY when I connect the tablet

I also don’t care if the program has to be in console or forms


How to lock brightness or remove slider on an android device. (Specifically a Lenovo Tab 7)

This is basically to stop a child from raising the brightness all the time. I have apps like App Lock to stop with tampering settings, but I haven’t seen anything to stop brightness. If anyone has any suggestions, it would be appreciated.

security – Someon offered me btc mine trough his mining device

Someone from the social network offered me a btc mine through his mining device. He asked me for an email address so he could create a mining wallet address for me. I gave it to him. I don’t know what he did, but very soon after that I received an email from Blockchain informing me that my wallet address had been created and that I could connect it directly to the mining stream.
After this I should deposit a certain amount of btc to this wallet address, which is now, supposedly connected to this gentleman’s mining device.
is this a scam attack or ..

Can an SD card be damaged because of different transfer speeds between a device and the card

I have a Nintendo Switch that accepts SD cards that transfer at speeds 60 – 95 MB/s


I bought and SD card that is UHS-1 compatible, but is slower in transfer speeds than what the console asks.

Can that SD card be damaged because of different transfer speeds between a device and the card ?
Do I need to format it before using that on a cell phone (or other device) ?

I have looked for this information, but this is the closest to what I need.

SD Card Read–Write Speed, Error and Recovery

This is also a similar question but not the same that I’m asking
Can a device ruin an SD Card or microSD card?

how to discover if a Samsung device is already registered with Knox Mobile Enrollment (KME)?

I’m asking this question as a end user not a Knox cloud admin. Bearing this in mind,

I’ve finished the first initial setup without allowing the device to connect to the Internet (and thus couldn’t be aware of any possible Knox enrollment prompt). And now I would like to discover if this device is already registered with Samsung Knox Mobile Enrollment (KME) and thus if it is a corporate-owned device or BYOD (any kinda work device)?

I shouldn’t do a factory reset for some reasons. How to verify that without giving the device a factory reset?

rom flashing – my device got a ROM flash by the seller prior to my purchase?

I bought a Galaxy Tab S6 a few days ago and I am going to verify if it is really brand-new.

Some facts: The production date of this device is in July 2020 and my purchase date is in February 2021.

First of all, the system date and time is not up-to-date and even confusing. The system date (on the day of my purchase) backs to January 3, 2019 (that is, 7 mounths prior to August 2019 when this device model released by the manufacturer for the very first time).

Besides, the system time doesn’t match the device region (UAE) local time and there is about 9 hours difference.

Finally, dates of files in Android folder are mostly January 1, 2019 (which indicates two days prior to my purchase and boot up) and other file dates are for two days later (January 3, 2019) when I purchased and booted the device.

Therefore I’m going to conclude that the seller might had flashed ROM into this device a couple days before he sold it to me and this device is not brand-new.

What is your opinion?

ios – Is there any way to send notifications via the speaker when a Bluetooth audio device is connected to an iPhone?

If an iPhone has a Bluetooth device connected the notification sounds (but not the phone ringer) are played only via the Bluetooth device, not the phone speaker. This causes problems for people who are in the habit of wandering around with their BT headphones connected, but not in their ear.

This is causing havoc with a friend of mine who never hears text message or other notifications.

Is there any way to change this?

networking – USB tethered device constantly changing public IP address

I recently switched from iPhone to Android (Galaxy S10e), and use the phone hotspot as my primary internet.

I connect the phone to a gli-net mini router (https://www.gl-inet.com/products/gl-ar750s/) through USB Tether, and from that (only have ethernet enabled on the mini router) to a netgear Nighthawk R7000 router which we use for wifi in the house.

The gli-net router has a firewall rule to keep the TTL at 64 (or was it 65??) so we can continue to get unthrottled speeds.

On the netgear router I have also disabled 2g wifi, and only use 5g.

The problem we have is that our IP address on connected devices changes with each web request. So if we go to https://www.whatsmyip.org, we have a new IP address at almost every refresh.

It seems like there are a few addresses the the laptops rotate between ..*.7/9/15.

The DHCP lease time on the routers is 12 hrs.

Do you have any ideas what I should look at next?

When we connect through a vpn on the laptop (protonVPN for example), our IP address doesn’t change at every request.

It worked with the iPhone, so I’m wondering if something is going on in the android I’m not aware of? oh, also, the phone service I’m using only allows 1 hotspot connection, which Android respects. The iPhone ignored that. Do you think the issue could be caused by the phone service + android only allowing 1 device? I assumed that if I tethered to the gli-net that it would see that as my one device..