23
votes
Accepted
How to permanently disable swap on Raspbian Stretch Lite
To avoid an error on startup regarding dphys service, try to disable swap on this way:
sudo dphys-swapfile swapoff
sudo dphys-swapfile uninstall
sudo update-rc.d dphys-swapfile remove
sudo apt purge ...
- 356
14
votes
Raspberry Pi 3 has less than 1GB memory available at OS level
If the output of vcgencmd get_mem arm && vcgencmd get_mem gpu is
arm=880M
gpu=128M
This means that GPU is using 128M.
This can be verified/changed in raspi-config Advanced Options, although ...
- 58.6k
12
votes
How to permanently disable swap on Raspbian Stretch Lite
I used to use sudo update-rc.d dphys-swapfile remove
I haven't tried recently so I'll assume that no longer works as you have tried using it.
Perhaps try CONF_SWAPSIZE=0 in /etc/dphys-swapfile
- 70.5k
10
votes
Accepted
Raspberry Pi 3 has less than 1GB memory available at OS level
First of all, I give my best regards to @Milliways for suggesting to check 2 simple commands.
vcgencmd get_mem arm && vcgencmd get_mem gpu
Where is the missing 128MB memory?
Even if both ...
- 1,185
9
votes
Accepted
C++ cout output on RPi 3B
ostream class has no methods to print volatile pointers, and a volatile pointer cannot be converted to a regular pointer without an explicit cast.
However, any pointer can be converted to bool: every ...
- 27.7k
9
votes
Accepted
Extra 16M memory on Pi2/Pi3
The Pi has a 30-bit (1024MB) address space (the top two bits are used for caching aliases).
A small amount of one of the aliases is used for gpu peripheral access.
The arm accesses gpu memory space ...
- 262
7
votes
Why do I have so many RAM disks?
That is nothing unusual.
RAM discs are commonly used for temporary file systems.
My Debian laptop
Filesystem Size Used Avail Use% Mounted on
udev 1.5G 0 1.5G 0% /dev
tmpfs ...
- 70.5k
6
votes
Accepted
Freeing up cache when memory is low
Before I ran a few commands on my raspberry pi I had less than 4 MB of memory left!
Wrong. You had 76.5 MB left.
total used free shared buffers cached
Mem: ...
- 58.5k
6
votes
Accepted
Memory Limit of Python3 in Raspberry 3
Your kernel could be build with 2G/2G memory split (giving 2GB of virtual address space to the kernel and leaving another 2GB for the applications). You can check that in kernel config:
zcat /proc/...
- 27.7k
6
votes
Accepted
More Memory on Raspberry Pi
I was wondering if there was any way to allow more ram
Not more physical RAM, but you can increase the amount of system memory by using swap, which is a region of secondary storage. Traditionally on ...
- 58.5k
5
votes
Accepted
Can Compute Modules provide clustering and high availability?
There is no reason you couldn't design a custom PCB and stick a bunch of compute modules on them if you desired. There are a few "gotchas" though.
This wouldn't be particularly powerful. The chips ...
- 11.9k
5
votes
Accepted
Raspberry pi class 4 vs Raspberry pi 2 class 10
Somewhat contra Jivings and Jacobm001, here's a test of two particular cards (class 4 and class 10) I did when I first got a pi:
Benchmarking SD cards, read speed is identical
There is a link ...
- 58.5k
5
votes
How can I install keybase (and dependencies) without running out of memory?
create a swap file with 4 GB of space:
This was my problum when installing docker i had to create a swap file and it worked same error code, so let me know if this works!
Source: This Post
...
- 569
5
votes
Unable to set GPU memory split on Raspberry Pi Zero W
Thanks to the forums over on raspberrypi.org I was able to find out the answer to this, so I am sharing it here for future reference...
ANSWER: The 128M of GPU RAM is still being reserved because I ...
- 993
4
votes
Accepted
Why do I have so many RAM disks?
Firstly, RAM disks are not the same thing as tmpfs.
There are many directories on your root drive that are used to store temporary files. These folders tend to have a lot of reading and writing going ...
- 156
4
votes
Accepted
Are Rpi1B 256MB / Rpi1B512 interchangeable using *the same* SD/card (Raspbian)?
I would expect the OS to be "smart" enough to "adapt" to the extra (or less) amount of RAM. But does it?
Yes. There are only two basic forms of pre-compiled kernel, one for the single core ARMv6 ...
- 58.5k
4
votes
Accepted
Raspberry PI 3 Increase Gpu Memory to 944
This is useless as you don't seem to run GPU RAM heavy OpenGL applications. You don't need more than 128MB GPU RAM to run videos smoothly as the hardware decoder will use only a fixed amount. So ...
- 2,702
4
votes
Accepted
What is the memory in the DS3232 RTC for?
@Dougie is absolutely correct, you can to whatever you want with this memory, and it will survive a power cut of the main supply as long as the battery is OK.
The reason for such memory is that in ...
- 516
4
votes
How to write protect in DS2431 Maxim EEPROM using Raspberry Pi
It is very helpful when working with electronic devices to read their data sheet. The electronics equivalent of RTFM, "Read the fine manual" is RTFDS. It will explain the features and electrical ...
- 51
3
votes
regarding how to measure memory usage on raspberry pi for a specific program
You may want to start by running top and locating your program in the list. It will look similar to this:
As you can see, there are 3 different memory metrics, each with its own gotchas:
VIRT - this ...
- 27.7k
3
votes
Why do I have so many RAM disks?
Short answer: it is just a fdisk peculiarity on latest versions. Alternatively you could also use parted and lsblk.
Extracted from this thread at AskUbuntu:
On later versions of fdisk the ...
3
votes
Accepted
What does libcofi do?
The source isn't exactly top rate (a 2013 thread from the archlinuxarm.org forums), but this seems to tally with your linked answer:
For those who don't know the libcofi was a small library that ...
- 10.7k
3
votes
Raspberry pi class 4 vs Raspberry pi 2 class 10
The class of a Micro SD card determines it's write time, NOT it's read time. Class 10 cards usually have a slower read time than Class 4 cards. Class 4 has a fast enough read and write speed for most ...
- 6,365
3
votes
Raspberry pi class 4 vs Raspberry pi 2 class 10
The difference between the class 4 and class 10 would be extremely obvious on the original RPi, and even more so on the RPi 2.
Even if you're using a read only filesystem, the boot time will be ...
- 11.9k
3
votes
Can Compute Modules provide clustering and high availability?
While not doing this with compute modules, I have 6 PI3's running together to test HA setups (database cluster sometimes, load balanced nginx servers other times). It's way cheaper to buy 6 pi's (and ...
- 326
3
votes
How to set up swap space?
It is a pity that the Raspberry Pis do not have GigaBit Ethernet but it is at least theoretically possible to have swap space on a network device - the Linux Terminal Server Project can offer it from ...
- 3,611
3
votes
Accepted
Minimum gpu_mem on π2
Normally I use a dynamic split (see below), but I tried this in config.txt:
gpu_mem_1024=16
Boots no problem, and subsequently:
> vcgencmd get_mem gpu
gpu=16M
> free
total ...
- 58.5k
3
votes
Accepted
Raspberry Pi with flash memory?
The compute module has upto 32GB eMMC flash memory on board. You will need some form of daughter board though:
https://www.raspberrypi.org/products/compute-module-3-plus-32gb/
- 6,827
3
votes
Accepted
RPI3B+ Chromium Freeze - RAM Swap
The memory installed on a Raspberry Pi is directly soldered and is not intended to be replaced or extended. Looking on the web, while there are quite a few posts asking for a method to add RAM, all ...
- 403
2
votes
New PI 2 B+ unusably slow, CPU and RAM not being used?
A totally obvious solution I'm afraid, have you expanded the file system? You can do this on Raspbian by running
sudo raspi-config
As I said, it's fairly obvious but easily overlooked and would ...
- 21
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