How to find out sd card partition in dev/block? In order to mount an ext4-formated sd card in Android I followed this guide.

In the bash script msd2.sh is followking command:

mount -t ext4 /dev/block/mmcblk1p1 /storage/extSdCard &amp;&amp; sleep 5 &amp;&amp; /system/bin/vold

So in this part the mmcblk1p1-partition shall be mounted in /storage/extSdCard.


How can I find out which of the partitions in dev/block is my sd-card ?


Furthermore I cannot mkdir a folder in /storage to have an equivalent mountpoint: mkdir failed for /storage/extSdCard, Read-only file system


How do I get read-write access of \storage ?


Info:


Phone: Sony Xperia Z1
Model number: C6903
Android version: 5.1.1
Build Number: 14.6.A.1.236
How can I find out which of the partitions in dev/block is my sd-card ?
  


By default, external memory card's partition is /dev/block/mmcblk1p1 in all devices.
(Unless if you have partitioned the memory card, then you should know which partition to use, for example, if you have partitioned 32GB memory card as first 16GB as FAT32 partition &amp; second 16GB as EXT4 partition, to use the EXT4 partition, you'll be using mmcblk1p2)


  
  How do I get read-write access of /storage ?
  


I hope by r/w access you mean creating a directory (mount point) to mount the external SD card.

You cannot do that after the device has booted, atleast since KitKat(?).The only way to do that would be by editing the ramdisk of your boot.img according to your requirement.