Re: [ANNOUNCE] util-linux-ng v2.17 (stable)

["H. Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>]

On 01/10/2010 10:36 PM, Martin K. Petersen wrote:
>>>>>> "Andreas" == Andreas Dilger <adilger-xsfywfwIY+M@public.gmane.org> 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 util-linux-ng" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html