>>>>> "david" == david <david@xxxxxxx> writes: >> 512-byte logical / 512-byte hardware (current) 512-byte logical / >> 4096-byte hardware (ATA, doing read-modify-write) 4096-byte logical / >> 4096-byte hardware (SCSI initially, ATA later) david> add to this good support for SSDs david> ?? logical / 128K hardware david> or similar. Yep. And that goes for RAID arrays too. For SCSI there some knobs we can query to get this information and my alignment changes are using those (and they are in turn what Willy's stuff hooks into). I've been lobbying the SSD vendors whose architecture is prone to misalignment problems to propose a similar set of knobs for ATA. But so far it's just been a lot of talking. My topology changes are a bit abstract in the sense that they expose: - smallest I/O you can submit without incurring a penalty (hw sector, raid chunk size) - optimal I/O size for the device in question - biggest I/O you can submit without incurring a penalty - alignment We can use these parameters to lay out partitions and filesystems optimally. Just like we currently do with XFS but implemented in a more generic way that all filesystems can use. -- Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
