>>>>> "Ted" == Ted Ts'o <tytso@xxxxxxx> writes: Ted> But min_io currently means the smallest size that we're allowed to Ted> write, correct? Without incurring a penalty, yes. That was conceived in the standards with 4K sectors and RAID RMW in mind. But I think it would apply to SSDs as well. Depending on how mkfs.* interpret the field, obviously. Ted> And the flash page size could be 128k and 512 byte writes might be Ted> perfectly OK; it's just that writes are more optimal at 128k, and Ted> would be even more optimal at the erbase block size of 4 megs. Yep. Just like in the RAID case where the writing the full stripe chunk is better than just a logical block. And a full stripe is even better. Ted> That's why I'm not sure it makes sense to use the existing fields, Ted> since it will confuse file system utilities that are reading those Ted> fields. Happy to add new fields if it makes sense. But right now ATA ACS doesn't even have anything corresponding to the SCSI fields that populate min_io and opt_io. -- Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
