Xiao, > If the upper layer submit 1GB request, SCSI will split them and handle > 32MB requests in default. If the upper layer wants SCSI to handle 1GB > one time, it needs to pass some information to SCSI, right? It is the device that defines its capabilities, not Linux. If the device states it wants 32MB per request, then that's what we'll issue. >> In NVMe there's a limit of 64K blocks per range and 256 ranges per >> request. So 8GB or 64GB per request for discard depending on the block >> size. So presumably it will take several operations to deallocate an >> entire drive. > > Could you tell the command how to check the block size. > blockdev --getsz tells the sector size of the device. It should not be the > block size you mentioned here. blockdev --getss will tell you the device's logical block size. -- Martin K. Petersen Oracle Linux Engineering
