diff --git a/block/vdi.c b/block/vdi.c
index 1ce18d5..362c898 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -405,19 +405,12 @@ static int vdi_open(BlockDriverState *bs, int flags)
         /* We only support data blocks which start on a sector boundary. */
         logout("unsupported data offset 0x%x B\n", header.offset_data);
         goto fail;
-    } else if (header.disk_size % SECTOR_SIZE != 0) {
-        logout("unsupported disk size %" PRIu64 " B\n", header.disk_size);
-        goto fail;
     } else if (header.sector_size != SECTOR_SIZE) {
         logout("unsupported sector size %u B\n", header.sector_size);
         goto fail;
     } else if (header.block_size != 1 * MiB) {
         logout("unsupported block size %u B\n", header.block_size);
         goto fail;
-    } else if ((header.disk_size + header.block_size - 1) / header.block_size !=
-               (uint64_t)header.blocks_in_image) {
-        logout("unexpected block number %u B\n", header.blocks_in_image);
-        goto fail;
     } else if (!uuid_is_null(header.uuid_link)) {
         logout("link uuid != 0, unsupported\n");
         goto fail;
@@ -426,6 +419,23 @@ static int vdi_open(BlockDriverState *bs, int flags)
         goto fail;
     }
 
+    if (header.disk_size % SECTOR_SIZE != 0) {
+        /* 'VBoxManage convertfromraw' can create images with odd disk sizes.
+           We accept them but round the disk size to the next multiple of
+           SECTOR_SIZE. */
+        logout("odd disk size %" PRIu64 " B, round up\n", header.disk_size);
+        header.disk_size += SECTOR_SIZE - 1;
+        header.disk_size &= ~(SECTOR_SIZE - 1);
+    }
+
+    if (header.disk_size >
+        (uint64_t)header.blocks_in_image * header.block_size) {
+        /* Old versions of qemu-img could create images with too large
+           disk sizes. We accept them but truncate the disk size. */
+        logout("large disk size %" PRIu64 " B, truncated\n", header.disk_size);
+        header.disk_size = (uint64_t)header.blocks_in_image * header.block_size;
+    }
+
     bs->total_sectors = header.disk_size / SECTOR_SIZE;
 
     s->block_size = header.block_size;
@@ -829,7 +839,10 @@ static int vdi_create(const char *filename, QEMUOptionParameter *options)
         return -errno;
     }
 
-    blocks = bytes / block_size;
+    /* We need enough blocks to store the given disk size,
+       so always round up. */
+    blocks = (bytes + block_size - 1) / block_size;
+
     bmap_size = blocks * sizeof(uint32_t);
     bmap_size = ((bmap_size + SECTOR_SIZE - 1) & ~(SECTOR_SIZE -1));