I tested the SD-card in my linuxmint PC. Here is can see 15,5 gB with the instruction : sudo fdisk -l
Disk /dev/mmcblk0: 15.5 GB, 15523119104 bytes
4 koppen, 16 sectoren/spoor, 473728 cilinders, totaal 30318592 sectoren
Eenheid = sectoren van 1 * 512 = 512 bytes
Sectorgrootte (logischl/fysiek): 512 bytes / 512 bytes
in-/uitvoergrootte (minimaal/optimaal): 512 bytes / 512 bytes
Schijf-ID: 0x000ebed2
Apparaat Opstart Begin Einde Blokken ID Systeem
/dev/mmcblk0p1 40960 143359 51200 c W95 FAT32 (LBA)
/dev/mmcblk0p2 143360 7395327 3625984 83 Linux
When I do the same with the SD-card in the OP PC2, I receive as result :
Disk /dev/mmcblk0: 14.5 GB, 15523119104 bytes
Device Boot start End Sectors size ID Type
/dev/mmcblk0p1 40960 143359 102400 50MB c W95 FAT32 (LBA)
/dev/mmcblk0p2 143360 7395327 7251968 3,5MB 83 Linux
I looks, something is wrong in the OP from the orangepi PC2. As said in my previous post, I used the orangepi PC quick start guide because there is no quick start guide for the OPPC2 available on the website.