Darrick, > T10 PI gives the kernel a means to associate its own checksums (and a > goofy u16 tag) with LBAs on disk. There haven't been that many actual > SCSI devices that implement it, Storage arrays have traditionally put their own internal magic in that tag space and therefore did not allow filesystems to use it. That has changed with the latest NVMe PI amendments which allow a larger tag (and CRC). The tag space can be split between storage and application/filesystem use. There are definitely interesting things that can be done in this area. -- Martin K. Petersen Oracle Linux Engineering