Lxw2015
Posts: 84
Joined: Fri Feb 12, 2016 4:05 am

SD card partition question

Sun Oct 11, 2020 5:08 pm

After I flash RPi image to SD(64G) card. the SD card has 2 partitions. 1 contains RPi OS(256MB), and another is empty even not formatted. I wonder how could Rasbian full Desktop OS fit into 256MB? and how the RPi use the parttion2?
and if I try to use the SD card for other purpose, I can only use partition 1, only 256M. how could I use the full SD card capacity ?

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DougieLawson
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Re: SD card partition question

Sun Oct 11, 2020 5:17 pm

That looks normal because older versions of Windows have no idea what EXT4 formatted partitions are nor why you'd need one so don't have any support in the OS for handling them.

The only rule is NEVER accept any offer by Windows to reformat/fix your broken partitions or you'll need to re-image the SDCard.
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GlowInTheDark
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Re: SD card partition question

Sun Oct 11, 2020 5:59 pm

To answer OP's question, if you want to use the entire card under Windows, then go ahead and let Windows reformat it.

Of course, it won't work on the Pi anymore after this, but OP's goal is to be able to use the whole card under Windows.

Edit to add: Many people have reported that putting the card into a digital camera (if you have one) and letting the camera reformat it, will make it once again usable under Windows. I've never had occasion to test this.

Footnote: Also, there are 3rd party drivers for Windows that allow it to access (read/write) the Linux partitions. Again, I've never had occasion to test this, but I'll say that I don't trust them to get it right. It doesn't sound like a good idea to me.
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W. H. Heydt
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Re: SD card partition question

Sun Oct 11, 2020 6:39 pm

Lxw2015 wrote:
Sun Oct 11, 2020 5:08 pm
After I flash RPi image to SD(64G) card. the SD card has 2 partitions. 1 contains RPi OS(256MB), and another is empty even not formatted. I wonder how could Rasbian full Desktop OS fit into 256MB? and how the RPi use the parttion2?
and if I try to use the SD card for other purpose, I can only use partition 1, only 256M. how could I use the full SD card capacity ?
If you boot your Pi from that card and then do "df", you'll see that the small partition is the "/boot" partition, and the rest of the card is formatted as EXT4 and contains all of the actual Linux stuff including the user account home directories, except for what is needed to boot the system (e.g. the Linux kernel, cmdline.txt--which is kernel parameters, and config.txt--which is system configuration data).

RonR
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Re: SD card partition question

Sun Oct 11, 2020 7:21 pm

Lxw2015 wrote:
Sun Oct 11, 2020 5:08 pm
After I flash RPi image to SD(64G) card. the SD card has 2 partitions. 1 contains RPi OS(256MB), and another is empty even not formatted. I wonder how could Rasbian full Desktop OS fit into 256MB? and how the RPi use the parttion2?

How did you write the RaspiOS image to your SD card? All that got there was the BOOT partition. The ROOT partition is totally missing (it's not a Windows display issue). You should see something similar to:
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After the first boot, the second partition will be auto-expanded to use the Unallocated space following it.

Lxw2015
Posts: 84
Joined: Fri Feb 12, 2016 4:05 am

Re: SD card partition question

Mon Oct 12, 2020 1:19 am

thank you all. now I understand that the second partition is EXT4, windows 7 won't recognize it. yes, I can use camera format it to get 64GB capacity.

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