Hi, How do I get the full size of my SD Card.

Hi, I’m new and just notest that my sd card is saying all I have left is. Free 1621 mbytes and used is 255 mbytes and it says the size is 1876 mbytes, my sd card is 8gb way is it showing that I only have 1621 mb. I went and did just like the document said on the raspberry pi .org website says, I’m using windows 7 formatted the sd card showed that it has 8gb. and then I used Win32DiskImager.exe to put the img on my sd card, did I miss something.

Andrea

No, you didn’t miss anything…

RISC OS uses something called Filecore to format and access its discs. Unlike other systems like FAT, NTFS, ext, and so on, Filecore doesn’t understand partitions (yet — there’s currently work happening on that front, I think). If Filecore is given an SD Card, it takes all of it over.

As such, the SD Card image for RISC OS is a bit of a fudge: it’s effectively completely Filecore, but with a FAT partition very carefully placed on the the top. Filecore is told that the area used by the FAT partition is a file (which appears as the DOS — ie. FAT32 — file $.!Boot.Loader), so that it doesn’t write over it.

The problem is, assembling this in the right way is quite fiddly, as the FAT32 partition must be placed correctly and Filecore’s disc map made to match. You can do it by hand, but it’s not simple (it involves a lot of messing around in sector editors). Thus the default RISC OS image is 2GB and can’t be resized: it is intended to fit most SD Cards, even if that wastes space on larger ones.

Fortunately there’s a tool to do the work for you. SystemDisc will set you back £12, and you can find it here: http://piccolosystems.com/disctools/systemdisc

Thanks Steve for the information. If I get a bigger sd card would that give me more space, just till I order systemdisc.

Andrea

If I get a bigger sd card would that give me more space

No: the image is fixed at just under 2GB¹, and will just use the first 2GB¹ of any card that it’s put on.

The problem is that resizing it requires the clever stuff that SystemDisc does, because the FAT partition and the file in Filecore’s discmap need to remain perfectly aligned at the end of the process. If they don’t, you’ll end up losing data quite quickly.

just till I order systemdisc

Assuming that it’s not an issue for you to place the order now, “delivery” is pretty much instantaneous: you just get access to a download from your account on Piccolo’s website.

Otherwise, you can resize images yourself with a sector editor. I’m not sure if there’s a publicly-available explanation of the process anywhere, however (it was covered in the Wakefield Club’s newsletter last June or July, but that’s subscription only).

¹ 1.8-mumble GB, IIRC.