Best practice to protect sd card (WIKI offers 2 options). Topic is solved

[Jan Jansen]

Hi all,

I want to protect my sd card against damage.

As far I can understand wiki offers 2 options:
1. Setting up a RAM drive on a Raspberry Pi;
2. Setting up overlayFS on Raspberry pi;

What’s he best practice? Why is this best practice not installed by default (like MQTT broker, NodeJS, Node-red)?

Thanks in advance.

[georgesattali]

Hello,
here's a free opinion, purely mine :
* Setting up overlayFS should be better, but it's complicated and not well documented on Internet, whereas setting up several RAM drive for often accessed directories is very easy, so if not perfect, a good solution.

The best practice is not yet available, and you're right, I hope that someone will do it. We already have a very good basis (Thank you very much gizmocuz).

Personally, I set up 3 ram drives (by adding theses lines to /etc/fstab) :

Code: Select all

tmpfs /tmp     tmpfs  defaults,nosuid,nodev,noatime,mode=0755,size=4M 0 0
tmpfs /var/log tmpfs  defaults,nosuid,nodev,noatime,mode=0755,size=6M 0 0

tmpfs /var/gai tmpfs  defaults,nosuid,nodev,noatime,mode=0755,size=6M 0 0

The first 2 are system standard, the third is for my "own personal usage". The question of setting a ram drive for /var/log can be discussed, it is my personnal choice.

I am very interested in other opinions or other enhancements.
Have a good day,
GD

[Egregius]

Isn't 6M to small for /var/log?
You 'may' assign more, it will only be assigned when in use. I have mine set to 300M on RPI2.
Ofcourse you have to clean you're logfiles now and then.
One thing to consider is logging to specific folders. Like nginx is default set to /var/log/nginx/...log so you need to alter those configs to.

[guus_b]

There is a third option to protect the SD card: https://www.raspberrypi.org/forums/view ... 29&t=44177
I use this on all three of my rpi's (2x Domoticz, 1x OSMC).

[woody4165]

There is a third option to protect the SD card: https://www.raspberrypi.org/forums/view ... 29&t=44177
I use this on all three of my rpi's (2x Domoticz, 1x OSMC).

Very well written document, it seems to be best solution.
In any case, SD or not SD, do you think that a daily/weekly reboot is needed to clean the system one in a while?

Thanks

[Egregius]

Why should you reboot? A Linux system should (almost) never reboot.

[woody4165]

Perfect, thanks!

[pvm]

You can also move your filesystem to iscsi on a nas

[Jan Jansen]

Thanks a lot for the ansers. "Move the filesystem to a USB stick/Drive" seems the best solution. I feel like a noob at this point. It seems difficult but I'll try.

I 'm not sure that I can start with a fresh Domoticz image. Woody4165 you know an answer to this?

Thanks in advance!!

[guus_b]

You don't need a fresh Domoticz image. The step sudo rsync -axv / /mnt in the procedure creates a mirror of the current situation of your SD card.
I would stop the domoticz service before running that command, though.

Code: Select all

sudo service domoticz.sh stop

[Jan Jansen]

I tried the suggestion of @ guus_b https://www.raspberrypi.org/forums/view ... 29&t=44177, without success. I got stuck very quickly (latest stable Domoticz).

Knipsel6.PNG (56.94 KiB) Viewed 3048 times

After the command (df -h) the line rootfs is missing.
After ( lsusb) , for me everything seems OK
After ( tail /var/log/messages) , I can not find the USB stick.

What’s wrong?

Thanks in advance

[Jan Jansen]

I just started with a fresh Jessie image (without Domoticz). I followed the instructions carefully https://www.raspberrypi.org/forums/view ... 29&t=44177.

Knipsel6.PNG (77.25 KiB) Viewed 3029 times

Got some errors wich I don't understand. I hope that somebody cab point me in a good direction.

Thanks

[Jan Jansen]

I took a break and then I tried again. I started reformatting the USB stick. It now works as desired.