mr_grow.sh allow you to grow your microraid.
If it is currently started, make sure to stop it.
The mdadm tool supports resizing only for software RAID levels 1, 4, 5, and 6.
./mr_grow.sh: <MAP> <NAME> <4k BLK CNT>
./mr_grow.sh 4T.map resizetest 2700000
Increasing /mnt/PAGXKNDT/resizetest/resizetest.1.rimg to 2700000 4k-blocks ...
Increasing /mnt/PCG4XHRB/resizetest/resizetest.2.rimg to 2700000 4k-blocks ...
Increasing /mnt/PAJXH1LT/resizetest/resizetest.3.rimg to 2700000 4k-blocks ...
Increasing /mnt/PAKY5VGT/resizetest/resizetest.4.rimg to 2700000 4k-blocks ...
Increasing /mnt/PBG0XTDT/resizetest/resizetest.5.rimg to 2700000 4k-blocks ...
Increasing /mnt/PBG0YBUT/resizetest/resizetest.6.rimg to 2700000 4k-blocks ...
Increasing /mnt/PBGAS33T/resizetest/resizetest.7.rimg to 2700000 4k-blocks ...
Increasing /mnt/PBG0W71T/resizetest/resizetest.8.rimg to 2700000 4k-blocks ...
/mnt/PAGXKNDT/resizetest/resizetest.1.rimg: /dev/loop20
/mnt/PCG4XHRB/resizetest/resizetest.2.rimg: /dev/loop21
/mnt/PAJXH1LT/resizetest/resizetest.3.rimg: /dev/loop22
/mnt/PAKY5VGT/resizetest/resizetest.4.rimg: /dev/loop23
/mnt/PBG0XTDT/resizetest/resizetest.5.rimg: /dev/loop24
/mnt/PBG0YBUT/resizetest/resizetest.6.rimg: /dev/loop25
/mnt/PBGAS33T/resizetest/resizetest.7.rimg: /dev/loop26
/mnt/PBG0W71T/resizetest/resizetest.8.rimg: /dev/loop27
Sleeping 3 seconds for kernel auto-detect ...
/dev/md126 has been assembled: clean
md126 : active raid5 loop27[8] loop26[6] loop25[5] loop24[4] loop23[3] loop22[2] loop21[1] loop20[0]
/dev/md/resizetest -> /dev/md126
mdadm: component size of /dev/md126 has been set to 10796928K
Array Size : 75578496 (72.08 GiB 77.39 GB)
Used Dev Size : 10796928 (10.30 GiB 11.06 GB)
You may now resize your FS