Raspberry PI 4 and microSD

Raspberry PI specific forum
User avatar
mk-soft
Always Here
Always Here
Posts: 5337
Joined: Fri May 12, 2006 6:51 pm
Location: Germany

Raspberry PI 4 and microSD

Post by mk-soft »

For testing, I quickly got myself a microSD Class 10, since I wanted (needed) to replace the OS that came with it.

Was not a good choice, just did not have another.

Now I have replaced the microSD with a "ScanDisk Extreme (64GB A2 V30)". Speeds Up To 160 MB/s Read and 60 MB/s Write. With a USB 3.0 CardReader I copied the OS. Tool is already included with Raspbeery.

The difference in speed is huge. :wink:

Translated with www.DeepL.com/Translator (free version)
My Projects ThreadToGUI / OOP-BaseClass / EventDesigner V3
PB v3.30 / v5.75 - OS Mac Mini OSX 10.xx - VM Window Pro / Linux Ubuntu
Downloads on my Webspace / OneDrive
infratec
Always Here
Always Here
Posts: 6818
Joined: Sun Sep 07, 2008 12:45 pm
Location: Germany

Re: Raspberry PI 4 and microSD

Post by infratec »

The SD card is always the problem of the PI.

Some day it will fail. The question is only when.
So always make copies with dd.
To avoid logging on the SD there is a project log2ram. But ...
you loose again RAM.
User avatar
mk-soft
Always Here
Always Here
Posts: 5337
Joined: Fri May 12, 2006 6:51 pm
Location: Germany

Re: Raspberry PI 4 and microSD

Post by mk-soft »

I have now tried log2ram.
Unfortunately, there was already about 800MB of journal data. After deleting this, it works. I have allocated 256 MB for the time being. Let's see how the need weighs.
My Projects ThreadToGUI / OOP-BaseClass / EventDesigner V3
PB v3.30 / v5.75 - OS Mac Mini OSX 10.xx - VM Window Pro / Linux Ubuntu
Downloads on my Webspace / OneDrive
Joris
Addict
Addict
Posts: 885
Joined: Fri Oct 16, 2009 10:12 am
Location: BE

Re: Raspberry PI 4 and microSD

Post by Joris »

Thanks infratec for that log2ram (didn't know that).

Also not unimportant are download paths of various software, eg from the browser.
I once downloaded a windows 10 install file 7 GB ... everything on the SD, which blocked RPI-OS and forced me to reinstall everything.
No warnings during this download process.
Yeah I know, but keep in mind ... Leonardo da Vinci was also an autodidact.
Marc56us
Addict
Addict
Posts: 1477
Joined: Sat Feb 08, 2014 3:26 pm

Re: Raspberry PI 4 and microSD

Post by Marc56us »

Also not unimportant are download paths of various software, eg from the browser.
I once downloaded a windows 10 install file 7 GB ... everything on the SD, which blocked RPI-OS and forced me to reinstall everything.
No warnings during this download process.
Yes, YAFIYGI ("You asked for it, you got it") is the motto of unix. No warning, no "are you sure ?" Unix is not designed to be a consumer or user-friendly system. The system is fast because it delegates the checks to the user. Don't rely too much on GUIs either.

You have to create partitions with quotas or use different disks (at least always separate the system data).

Note that this would not have blocked at all because un*x always reserves free disk space and inodes so that the administrator (root only) can take over, even if a program tries to saturate the system.
infratec
Always Here
Always Here
Posts: 6818
Joined: Sun Sep 07, 2008 12:45 pm
Location: Germany

Re: Raspberry PI 4 and microSD

Post by infratec »

If your free disk space is 0, you run into big trouble.
You can not login via ssh, even as root it is not possible.

You really need the console login to delete some files.
Marc56us
Addict
Addict
Posts: 1477
Joined: Sat Feb 08, 2014 3:26 pm

Re: Raspberry PI 4 and microSD

Post by Marc56us »

By default, Unix/Linux reserves 5% (now less) of each partition for the root user.
This reserve is not displayed when using 'df'.
Now, of course, you must not use root for downloads...
Yes, you can log to console via ssh on a full filesystem (fullfiled by normal user) thankfully for admins.

https://unix.stackexchange.com/question ... system-why
User avatar
C87
Enthusiast
Enthusiast
Posts: 176
Joined: Mon Jul 17, 2017 7:22 am
Location: Cotswolds England

Re: Raspberry PI 4 and microSD

Post by C87 »

On SDCard speeds, the data I found online had the Samsung Pro Extreme as the fastest.
When I tested two I bought against the Sandisk it does appear to be the case.
If it's falling over......just remember the computer is never wrong!
Post Reply