Re: compass update

Basil Gunn

Hi Bernard,
I have a solution that worked for me.

From your description you want a usb adapter with a microSD card to auto
mount when you plug it in to an RPi USB slot. When I do this on my
workstation which is a heavily modified Ubuntu distro it automounts the
two partitions, boot & rootfs to mount points /media/<user_name>/boot &

I have this working as described above on my RPi using a usbmount
package but not the current version in the Raspbian repo. This version
(0.0.22) only partially worked ie. it only mounted the /dev/sda1
partition and not both partitions. To get the exact functionality seen
on my workstation I had to build the latest version from this git repo:

Follow the instructions here:
Automatically Mount USB Drives On Ubuntu Or Debian Server With USBmount

Precede these instructions with:
sudo apt-get install lockfile-progs

Follow these instructions with
sudo dpkg -i usbmount_0.0.24_all.deb

To test: After inserting the usb adapter I look at the last 2 lines of
'df -h', that should look like this:

/dev/sda1 44M 23M 22M 51% /media/usb1
/dev/sda2 15G 4.3G 9.6G 31% /media/usb0

Also look at the mount points in /media/pi which are symlinks to /media/usb0 and
/media/usb1 and you should see the 2 partitions used on an RPi mSD card.

ls -l /media/pi
total 7
drwxr-xr-x 3 pi pi 2560 Dec 31 1969 boot
drwxr-xr-x 21 root root 4096 Nov 18 22:45 rootfs

Let me know if this works for you. Also look at the permissions of the
directory of the mount point you want to copy or modify files on. You
will have to match those permissions.

There is a stunning amount of bad or old information on the web
regarding this topic and I went down a path of modifying my udev config
and rendered my RPi unbootable. I didn't spend time figuring out what I
did wrong so my advice is do NOT muck with udev to get this to work.


f6bvp <f6bvp@...> writes:


I agree my description was not clear.
What you report is exactly the same as what df command reports when I plug in a microSD card into USB port of my RPi with Compass Linux.
The issue is when I add another microSD card into another USB port. This one is what I called a second SD card, not counting the Compass System one.
This last SD card is not detected and not mounted. Thus I cannot use it to save files from the other microSD.
However, I noticed that dev/sdb1 and /dev/sdb2 are reported by command fdisk -l (l for list).
I don’t know how to mount these sdb devices manually.
It would be more convenient if both additional device cards could be mounted at the same time to facilitate saving files from one place to another.


Le 19 mai 2019 à 22:56, Basil Gunn <@basil860> a écrit :

Are you plugging the second microSD card into a USB port on the RPi or
your workstation? What OS is on your workstation? Try df -h before &
after you plug the microSD card in. I don't think I am understanding
what you are doing.

I just tried it on my RPi and the microSD card shows up as device
/dev/sda1 & /dev/sda2

$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/root 15G 5.0G 9.1G 36% /
devtmpfs 460M 0 460M 0% /dev
tmpfs 464M 0 464M 0% /dev/shm
tmpfs 464M 13M 452M 3% /run
tmpfs 5.0M 16K 5.0M 1% /run/lock
tmpfs 464M 0 464M 0% /sys/fs/cgroup
/dev/mmcblk0p1 44M 22M 22M 50% /boot
tmpfs 93M 0 93M 0% /run/user/1000
/dev/sda1 44M 23M 22M 51% /media/pi/boot
/dev/sda2 15G 4.3G 9.6G 31% /media/pi/rootfs


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