Hi Mirzak,
ext4 mounted in RW change ~ 1k, I’ve tested it loop mounting ext4 fs
➜ qemux86-64 git:(develop) ✗ dd if=image-qemux86-64.uefiimg of=1 skip=49152 count=2064384
2064384+0 records in
2064384+0 records out
1056964608 bytes (1.1 GB, 1008 MiB) copied, 4.43723 s, 238 MB/s
➜ qemux86-64 git:(develop) ✗ dd if=image-qemux86-64.uefiimg of=2 skip=49152 count=2064384
2064384+0 records in
2064384+0 records out
1056964608 bytes (1.1 GB, 1008 MiB) copied, 4.42777 s, 239 MB/s
➜ qemux86-64 git:(develop) ✗ sha256sum 1 2
8dffecc1d550f85ff202f5a051b732cf97e6944e52ef3c68ea66bd7c4359bdce 1
8dffecc1d550f85ff202f5a051b732cf97e6944e52ef3c68ea66bd7c4359bdce 2
➜ qemux86-64 git:(develop) ✗ sudo mount -o,loop 2 /mnt/2
➜ qemux86-64 git:(develop) ✗ umount /mnt/2
➜ qemux86-64 git:(develop) ✗ sha256sum 1 2
8dffecc1d550f85ff202f5a051b732cf97e6944e52ef3c68ea66bd7c4359bdce 1
857f24207987f5c4a3b55e5c5c3b92650b3bf5f185aeb4955e6a77b8ce8cd3f5 2
➜ qemux86-64 git:(develop) ✗ cmp 1 2
1 2 differ: byte 1069, line 1
Best,
Mauro