This read-only counter tracks the total number of write operations performed on this disk device since the host last booted. Admins use it alongside diskIONWritten to calculate average write size and monitor write operation rates, useful for identifying a disk under a heavy small-write workload. A disk with a high diskIOWrites count but relatively low diskIONWritten would indicate many small write operations, a pattern that can stress disk I/O more than fewer, larger writes.