macos – You may not install to this volume because the computer is missing a firmware partition

I have a macbook pro 2015 model. The internal ssd died and thanks to the internet recovery mode, i managed to install El Captain on an external ssd drive.

I’m trying to upgrade to Big Sur, but the option to choose my external ssd during installation is greyed out with the message

“You may not install to this volume because the computer is missing a
firmware partition”.

Is it possible to install any macos higher than 10.15 on an external ssd?

hardware – Ubuntu 20.04.03: computer Freezes randomly in rare circumstances

Five days ago I installed Ubuntu 20.04 LTS on my computer. As the title says, from time to time the computer would freeze completely, and I have no chance of giving any input to the machine since mouse and keyboard do not work. It doesn’t happen regularly, but when it does I’m forced to turn off the computer using the power button.
This is my hardware configuration

CPU: AMD Ryzen 5 1600X Six-Core Processor
GPU: AMD Radeon RX580X
MOBO: MSI B450 Tomahawk Max
RAM: 4GBx2 Crucial Ballistix Sport (ddr4, 2400 MHz)

Running the command free -h this is the output

total        used        free      shared  buff/cache   available

Mem:          7.8Gi       2.4Gi       3.6Gi        66Mi       1.7Gi       5.0Gi
Swap:         2.0Gi          0B       2.0Gi

Thank you for your attention.

basic terminology – Computer Science Stack Exchange

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installation – How to do Batch install multile apks from windows computer to Android box

I want to batch install apks from my desktop directly. Such as I downloaded many apks on the windows desktop i also have them on a USB stick and want to install apks without actually touching my android for each install I want to auto push like 100 apks to my android box without needing to do one by one or without needing to click install and done for each etc.

I used to install one by one by downloading each manually and then doing the install for each and every one.
I then started using apk installer app which at least allows me to load all my apks on the stick then it scans and does the install for each which is handy but I still needed to click install and done for each of them which sucks when it’s alot of apks.

I came across another post on this forum and it works perfect however the process only works from my android phone to windows pc I need the process to work from an android box not a android phone.

The process I used for the phone was outlined on the following link:

Batch install apks from computer to Android without actually touching my Android

Can anyone help to have this process done from android box vs android phone as the post above works 100% but only for phone not android box and i can’t get android box seen or recognized by the windows pc

How to do this?

❕NEWS – Internet computer to offer free 10,000 NFT |

ICpunks the NFT section of the general purpose blockchain , internet computer has expressed that they are very much happy to join the NFT world and that they have plans to release a future NFT marketplace.

They also promise that they will release 10,000 free NFT to some of their users. The criteria for receiving this is not yet revealed.

sound – why can’t I install Ubuntu on my computer

I’ve just installed Ubuntu 20.04 on my 13 inch 2015 MacBook Pro. When I go to the Bluetooth section in Settings, I can see my wireless headphones listed. The headphones are in their pairing mode, but when I click it on list it never connects. I’ve tried with three different sets of Bluetooth headphones (Airpods Pro, Airpods, and Bose QC35). What should I do to get my laptop to connect to Bluetooth devices? I know that Bose QC35 headphones work because I’ve used them with my desktop running 20.04.

privacy – How do I secure personal data on my computer when my employer installs monitoring software?

I have been working for a 100% virtual company for over a year, using my personal computer and I am fine with that. We were bought and now the parent company wants to add monitoring software to our personal computers. The challenge is preventing my employer from having access to non-employment related information. Another challenge is if my company gets hacked, I don’t want my personal information on the dark web.

I have a Macbook Pro 2019 and am considering adding a new APFS to house only company information and programs. Will that work if I create a separate user name and password for this new APFS?

I realize the best way is to buy a separate computer for work, however I’d rather not spend the extra money.

drivers – How to remove an audio output device from my computer?

I am using Displaylink driver to use my Dell D3100 dock for my 2 external monitors. But in my sound profile, whenever I boot my laptop or disconnect from my headphones, my computer reverts to the Dock audio as its default audio output device. Its incredibly annoying. I don’t want to demove my Displaylink driver as a result but how can I get rid of this?

~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC3266 Analog [ALC3266 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 7: HDMI 1 [HDMI 1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 8: HDMI 2 [HDMI 2]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 9: HDMI 3 [HDMI 3]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 10: HDMI 4 [HDMI 4]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: Dock [Dell D3100 USB3.0 Dock], device 0: USB Audio [USB Audio] <-- This is the problem
  Subdevices: 1/1
  Subdevice #0: subdevice #0

computer networks – Can you explain this token bucket example?

Suppose the token-bucket specification is TB(1/3 packet/ms, 4 packets), and packets arrive at the following times, with the bucket initially full:

0, 0, 0, 2, 3, 6, 9, 12
After all the T=0 packets are processed, the bucket holds 1 token. By the time the fourth packet arrives at T=2, the bucket volume has risen to 1 2/3; it immediately drops to 2/3 when packet 4 is sent. By T=3, the bucket volume has reached 1 and the fifth packet can be sent. The bucket is now empty, but fortunately the remaining packets arrive at 3-ms intervals and can all be sent.


What I know-:

Token bucket algorithm-:
1 token added to bucket in every $Delta t$ time.

For a packet to be transmitted, it must destroy the token.
That is all I know about token bucket algorithm

As far as the question is considered-:



r=token fill rate token/sec

$B_{max};$=Bucket Capacity

Complex `struct`s in rust – Computer Science Stack Exchange


I recently started learning the rust programming language.

Suppose you want to create some complex struct, for example – a graph.

I can see two possible implementations of this:

The first, uses Rc to create multiple ownership (so that the nodes own directly other nodes). The struct, might look similar to this:

struct Node {
   neighbors: Vec<Rc<Node>>,

However, using this implementation, one cannot “hold” the entire graph at once.

The second implementation will have the ownership be held by a wrapper graph object, and the nodes will only have references to the other nodes instead of actually owning them:

struct Node {
    neighbors: Vec<&Node>,

struct Graph {
    nodes: Vec<Node>,

In this implementation, we do have acess to the entire graph at once (through the Graph struct). However, now when deleting nodes in the graph we have to do an operation that takes $O(n)$ time (removing the node from the nodes list).

In my opinion, the second implementation is better – since it is cleaner and cannot cause memory leaks. However I wouldn’t like to have that extra $O(n)$ cost when deleting nodes (as opposed to $O(deg(v))$ in the first implementation).


I’m having trouble understanding how the borrowing rules (without using unsafe) can still allow me to create such an implementation. Does anyone know a feature of Rust that can help in this case? Thanks!

Honestly, I don’t know if this fits this site or the SO site, so please tell me in the comments if I need to move this question there 🙂