Initial remote commit

test/hh.sh

@@ -0,0 +1,54 @@
+python3 -c "
+CHUNK = 128*512
+LV_START = 5120000*512
+VIRT_SIZE = 9372172288*512
+
+def read_virt(offset, length):
+    result = bytearray(length)
+    pos = offset
+    remaining = length
+    with open('/dev/md0','rb') as f:
+        while remaining > 0:
+            group     = pos // (5*CHUNK)
+            in_group  = pos % (5*CHUNK)
+            chunk_idx = in_group // CHUNK
+            intra     = in_group % CHUNK
+            seg_len   = min(CHUNK-intra, remaining)
+            dst_off   = pos - offset
+            if chunk_idx != 4:
+                phys = LV_START + group*4*CHUNK + chunk_idx*CHUNK + intra
+                f.seek(phys)
+                data = f.read(seg_len)
+                result[dst_off:dst_off+len(data)] = data
+            pos += seg_len
+            remaining -= seg_len
+    return bytes(result)
+
+# Check last 8MB of virtual disk
+last_8mb_start = VIRT_SIZE - 8*1024*1024
+print(f'Checking last 8MB: virtual bytes {last_8mb_start} to {VIRT_SIZE}')
+print(f'= virtual sectors {last_8mb_start//512} to {VIRT_SIZE//512}')
+
+data = read_virt(last_8mb_start, 8*1024*1024)
+nonzero = sum(1 for b in data if b != 0)
+zero_runs = 0
+in_zero = False
+for b in data:
+    if b == 0 and not in_zero:
+        in_zero = True
+        zero_runs += 1
+    elif b != 0:
+        in_zero = False
+
+print(f'Non-zero bytes: {nonzero} / {8*1024*1024}')
+print(f'Zero runs: {zero_runs}')
+print(f'First 32 bytes: {data[:32].hex()}')
+print(f'Last 32 bytes: {data[-32:].hex()}')
+
+# Find first non-zero from the end
+for i in range(len(data)-1, -1, -1):
+    if data[i] != 0:
+        print(f'Last non-zero byte at offset {i} from last_8mb_start')
+        print(f'= virtual byte {last_8mb_start+i}')
+        break
+"