Newly created bitmap files should not indiscriminately overwrite old ones
Split off bug 1105709.
The current bitmap writer code passes OS_FILE_OVERWRITE to os_file_create, thus if an old file happened to be there with the same name, it was destroyed.
As the old bitmap files should not be laying around, it's better to make this situation an error.
Zero-sized old files are a special case, they might occur during regular bitmap tracking (i.e. RO workload only between server restarts), and they should be overwritten.
- Newly created bitmap files should indiscriminately overwrite old ones
+ Newly created bitmap files should not indiscriminately overwrite old