After writing an SD card image, is the remaining space usable?

Question

Forgive me if this is basic, because I'm used to writing CD images, I'm not sure how this works. The Raspbian image is about 440MB (zipped at least). If I write the image onto a 16GB card, will all the remaining space on the card be usable for data?

score 10 · Accepted Answer · edited Apr 13 '17 at 12:56

10

Yes, you can repartition your card to reclaim the unused space. If you are using Raspbian then you have the option to do this as part of the initial boot. Otherwise you can refer to "How can I resize my / (root) partition?" for more information.

edited Apr 13 '17 at 12:56

Community

1

answered Aug 02 '12 at 20:03

Steve Robillard

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Thanks. So the Pi can simultaneously be booting from one partition while reading data from another? – Sputnik Aug 02 '12 at 20:05
Steve I thought Debian image resized it self on first boot.. but I cannot remember where I read it. – Piotr Kula Aug 02 '12 at 20:06
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@ppumkin it does not auto resize, but it does have a startup option to do so. I will edit my answer to reflect that. – Steve Robillard Aug 02 '12 at 20:13
The link to the other question was correct, and an extra answer should be added there. – Alex Chamberlain Aug 02 '12 at 20:17
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@Spütnik the default image you load on the card already has two partitions a boot partition and a root partition. What the startup script does is expand the root partition to utilise the entire disk capacity. As for accessing two partitions simultaneously I am not familiar enough with the low level details of SD Card access to answer. To clarify do you want to create a separate data partition? – Steve Robillard Aug 02 '12 at 20:19
Only one partition can literally be accessed at a time, but just as on magnetic media it is possible to have multiple partitions mounted concurrently. The operating system is responsible for multiplexing their operations onto the single physical device - normally this is transparent, though if you hit the performance limits of the storage device that would affect operations on all partitions. – Chris Stratton Aug 02 '12 at 20:37
@SteveRobillard I worded the question in a misleading way. Your response makes perfect sense and answers what I meant to say, cheers! :) – Sputnik Aug 02 '12 at 21:19

score 0 · Answer 2 · answered Feb 19 '17 at 12:14

Raspbian images do resize themselves after boot , so that the second partition including filesystem take up all space on the card. You would need a GParted live CD and an SD card reader to reverse that. Don't forget that Windows refuses to autodetect multiple partitions on removable drives and does not support Raspbian Linux' ext4 format at all.

After writing an SD card image, is the remaining space usable?

2 Answers2