With asynchronous replication, order is preserved, but the write is allowed to complete without waiting for an acknowledgement from the target node that the write has been received there.
Waiting 24 hours allowed the Sun to rise just north of east and arc back to an exactly eastern alignment for the photo.
春分过24小时后太阳应该从东方偏北升起，沿弧线上升一会儿后就正好出现在照片中的东方。
3
The earlier NFS mount option intr was a way out of interrupting NFS client processes waiting for some event, but it allowed all interruptions, not just one by deadly signals (like TASK_KILLABLE).