On 26/10/2022 20:33, R.Wieser wrote:
> In my case using a NOOBS install there are four partitions

That must be to cater for more than you need. My straight RASPIOS is
only two

--
How fortunate for governments that the people they administer don't think.

Adolf Hitler

On 26/10/2022 20:33, R.Wieser wrote:
> Chris,
>
>> blkid and lsblk will give info about unmounted but connected partitions as
>> well as mounted partitions.
>
> Thanks. lsblk seems to be the one which can, when asked nicely, output the
> partition label.
>
>> The boot prtition can be read on any Windows machine. Both partitons can
>> be read on any Linux/Unix machine.
>
> In my case using a NOOBS install there are four partitions (ignoring the
> Extended partition which can't be mounted). Two FAT (off of which Windows
> ofcourse only wants to show one, 'cause removable media) and two Linux
> partitions (which are the ones that get auto-mounted). Accessing one of the
> FAT partitions from within the RPi takes more work.
>
NOOBS partitioning (I have never used it!!) caters for more than one OS
installation (AFAICS), so has >2 partitions. It includes a recovery
partition and a NOOBS data partition.
For an explanation, see this pdf -
https://www.brobwind.com/wp-content/uploads/2015/12/NOOBS-partitioning-explained-%C2%B7-raspberrypi_noobs-Wiki-%C2%B7-GitHub.pdf
I found it by searching 'Raspberry Pi NOOBS four partitions'

Unless you _want_ >1 OS on the SD card, stick to downloading an OS and
writing the card as recommended previously.

If you have a Windows PC, install VirtualBox and a Linux distro of your
choice. Or WSL2 can mount ext4. See -
https://learn.microsoft.com/en-us/windows/wsl/wsl2-mount-disk

--
Chris Elvidge
England

"Chris Elvidge" <chris@mshome.net> wrote in message
news:tjc89c$2i0sh$1@dont-email.me...
> NOOBS partitioning (I have never used it!!) caters for more than one OS
> installation (AFAICS), so has >2 partitions. It includes a recovery
> partition and a NOOBS data partition.
> For an explanation, see this pdf -
> https://www.brobwind.com/wp-content/uploads/2015/12/NOOBS-partitioning-explained-%C2%B7-raspberrypi_noobs-Wiki-%C2%B7-GitHub.pdf

NOOBS is a good easy starting point for a straightforward computer with
nothing "clever" about the setup. But it is not very flexible.

I discovered this after I installed NOOBS and Raspbian on a 16 GB card and
later wanted to move the filesystem onto a 32 GB card so I had a bigger
"system drive". It was easy to copy the 16 GB card to a 32 GB card with
Win32 Disk Imager or a similar tool. But partition-expansion tools would not
work: no matter what I tried I still had a 16 GB partition on a 32 GB card
with the other 16 GB unused. There was something about the way NOOBS creates
partitions that did not allow the main system partition to be enlarged to
use all the unallocated space.

So I started again, installing from scratch. I forget now why 16 GB wasn't
enough disc space, given that most of the data on the Pi was being saved to
an external spinning HDD which I mounted to a directory below /home/pi/.

On 2022-10-25 13:04:42 +0000, R.Wieser said:
>>
>
> The biggest problem is that even that "Micro QR" is a 15x15 grid,
> making, on a 9x9mm surface, its squares less than a mm across ...

Nonetheless, it does work - but I'm not saying it's the best way, just
another string to your bow.

--
not_me

On 2022-10-25, The Natural Philosopher <tnp@invalid.invalid> wrote:
> On 25/10/2022 14:12, R.Wieser wrote:
>>
>> And I read somewhere I had to create that "mnt" directory first ? You do
>> not seem to do so.
>>
>> And a question : do you know wat happens when you (try to) eject the USB
>> dongle containing the uSD card you just mounted a partition of ? I would
>> not like to have either the boot uSD or the mounted one trashed.
>>
> umount /mnt
>
> /mnt may or may not be created by default - I think /media/<username> is
> often used to mount removable drives at least on my desktop linux

/mnt is the traditional parent directory for mount points of
miscelleneous filesystems that don't have a more natural home within
the hierarchy e.g. /usr or /home may well be mount points themselves.
It's essentially an administrator's convention when filesystems
are manually mounted.

A mount point in /media, /var or possibly a few other options are
those automatically mounted by your desktop environment. Traditional
Unix never automatically mounted anything, both because of potential
security issues or simply because historically there have been
plenty of other things you might do with removable media other than
put an FS on it.

--
Andrew Smallshaw
andrews@sdf.org

The Natural Philosopher <tnp@invalid.invalid> wrote:
> On 26/10/2022 12:14, Martin Gregorie wrote:
> > $ df -h
> >
> > works well if you just want to see what storage devices are mounted, their
> > sizes and free space.
> >
>
> Not on a pi. df -h reports "/dev/root mounted on /"
>
> There is no /dev/root.

That's because the root partition is supplied by UUID on the command line
(on a Pi 1 running Pi OS from about a week ago):

$ cat /proc/cmdline
coherent_pool=1M snd_bcm2835.enable_compat_alsa=0 snd_bcm2835.enable_hdmi=1
video=Composite-1:720x480@60i vc_mem.mem_base=0x1ec00000
vc_mem.mem_size=0x20000000 console=ttyAMA0,115200 console=tty1
root=PARTUUID=c5881c32-02 rootfstype=ext4 fsck.repair=yes rootwait

Because it's mounted by UUID rather than a device node, the path is
nominally /dev/root but that isn't a device node that needs to exist.

However, separately the UUID can be resolved:

$ ls -l /dev/disk/by-partuuid/
total 0
lrwxrwxrwx 1 root root 15 Sep 22 01:36 c5881c32-01 -> ../../mmcblk0p1
lrwxrwxrwx 1 root root 15 Sep 22 01:35 c5881c32-02 -> ../../mmcblk0p2

Basically, I think this is because the bootloader (GPU etc) is selecting
which partition to use as the rootfs and supplying it as a cmdline flag,
rather than being set by device node in the Linux world.

Theo

On 30/10/2022 10:28, Theo wrote:
> The Natural Philosopher <tnp@invalid.invalid> wrote:
>> On 26/10/2022 12:14, Martin Gregorie wrote:
>>> $ df -h
>>>
>>> works well if you just want to see what storage devices are mounted, their
>>> sizes and free space.
>>>
>>
>> Not on a pi. df -h reports "/dev/root mounted on /"
>>
>> There is no /dev/root.
>
> That's because the root partition is supplied by UUID on the command line
> (on a Pi 1 running Pi OS from about a week ago):
>
> $ cat /proc/cmdline
> coherent_pool=1M snd_bcm2835.enable_compat_alsa=0 snd_bcm2835.enable_hdmi=1
> video=Composite-1:720x480@60i vc_mem.mem_base=0x1ec00000
> vc_mem.mem_size=0x20000000 console=ttyAMA0,115200 console=tty1
> root=PARTUUID=c5881c32-02 rootfstype=ext4 fsck.repair=yes rootwait
>
> Because it's mounted by UUID rather than a device node, the path is
> nominally /dev/root but that isn't a device node that needs to exist.
>
Then its pointless labelling
The desktop linux pdesnt do it...e,g.

$df -h

Filesystem Size Used Avail
Use% Mounted on
udev 3.8G 0 3.8G
0% /dev
tmpfs 784M 1.7M 783M
1% /run
/dev/sda5 234G 68G 155G 31% /
tmpfs 3.9G 0 3.9G
0% /dev/shm
tmpfs 5.0M 4.0K 5.0M
1% /run/lock
tmpfs 3.9G 0 3.9G
0% /sys/fs/cgroup
/dev/sda1 511M 4.0K 511M
1% /boot/efi
784M 88K 784M 1% /run/user/1000

Both sda1 and sda5 exist

ls -l /dev/disk/by-partuuid/
total 0
lrwxrwxrwx 1 root root 10 Oct 17 05:41 51cec085-01 -> ../../sdb1
lrwxrwxrwx 1 root root 10 Oct 17 05:41 b1aaf3a7-01 -> ../../sda1
lrwxrwxrwx 1 root root 10 Oct 17 05:41 b1aaf3a7-02 -> ../../sda2
lrwxrwxrwx 1 root root 10 Oct 17 05:41 b1aaf3a7-05 -> ../../sda5

> However, separately the UUID can be resolved:
>
> $ ls -l /dev/disk/by-partuuid/
> total 0
> lrwxrwxrwx 1 root root 15 Sep 22 01:36 c5881c32-01 -> ../../mmcblk0p1
> lrwxrwxrwx 1 root root 15 Sep 22 01:35 c5881c32-02 -> ../../mmcblk0p2
>
>
> Basically, I think this is because the bootloader (GPU etc) is selecting
> which partition to use as the rootfs and supplying it as a cmdline flag,
> rather than being set by device node in the Linux world.
>
> Theo

--
There is nothing a fleet of dispatchable nuclear power plants cannot do
that cannot be done worse and more expensively and with higher carbon
emissions and more adverse environmental impact by adding intermittent
renewable energy.