On 9/18/18 9:20 AM, David Teigland wrote: >>> I'm betting that the underlying device advertised a logical/physical >>> sector size of 512 bytes to mkfs, and then adding pmem as the cache >>> device changed the logical volume from a 512 byte sector device to a >>> hard 4k sector device. > Yes > > I've been dealing with this by just using -s size=4096. > So the risk here - in general - is that using a sector size larger than the advertised physical sector size may - in general - lead to metadata IOs that are not atomic, when they are required to be so for consistency. -Eric
