SDcard format

when you need to format a sdcard for windows (phone) in linux:

sudo mkdosfs /dev/sdc1 -s 64 -F 32

-F is filesystem (32 is vfat/FAT32)
-s is the allocation size multiplier (for disks < = 16 GB it's usually based on a sector size of 512byte) how to find out sector size? fdisk! root@lando:~# fdisk -l /dev/sdc1
Disk /dev/sdc1: 1.9 GiB, 1973416448 bytes, 3854329 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x00000000
root@lando:~#

16×512 = 4K allocation size (standard for small cards)
64×512 = 32K allocation size (Lumia Phones from 4 – 32 GB)
(larger cards (64 GB and up) need exFAT and 128 kB allocation size for Lumia)

NOTE: for larger sector sizes you have to change the formula accordingly