On 01/10/2010 10:36 PM, Martin K. Petersen wrote: >>>>>> "Andreas" == Andreas Dilger <adilger@xxxxxxx> writes: > > Andreas> I agree whole heartedly. We steer users very sharply away from > Andreas> using partitions at all, because on h/w RAID devices the > Andreas> 512-byte offset from fdisk completely kills RAID-5/6 > Andreas> performance. > > I don't have a problem aligning to 1MB (taking alignment_offset into > account) by default but there needs to be an easy override. There are > RAID arrays that internally compensate for the legacy 63 sector offset > and we'll cause misalignment if we start at 1MB on those. > > I'm heavily lobbying our storage partners to make sure they fill out the > right SCSI bits if their LUNs are not naturally aligned. But there are > obviously going to be legacy devices out there that will need manual > alignment compensation. > Yes, but we shouldn't default to braindead mode. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
