Messages in this thread | | | Date | Wed, 17 Mar 2010 13:51:01 +1100 | From | Kevin Easton <> | Subject | Re: ATA 4 KiB sector issues. |
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James Bottomley wrote: > On Wed, 2010-03-17 at 00:20 +0900, Tejun Heo wrote:
...
> > Well, the thing is that > > > > * Anything remotely modern (>= XP) doesn't give a hoot about cylinder > > alignment. > > > > * Anything older (<= 2000) is very likely to get confused with custom > > geometry starting from the BIOS itself. For those cases, the only > > thing we can do is aligning partitions to cylinders abiding BIOS > > supplied geometry parameters which will usually be 255/63. > > > > So, using custom geometry doesn't help compatibility at all. > > Our partitioning tool still obey the integral cylinder rule ... we can > argue about whether they should, but what we need is a strategy for > fixing what is rather than what should be.
James / Tejun,
Can't we fix the problem by defaulting to aligning partitions to start on an LBA that is a multiple of 64260 ?
Such partitions will always be 4KiB-aligned, *and* start-of-cylinder aligned (assuming 255/63, as seems to be the norm).
Sure, that reduces your partition granularity to almost-32-MiB, but that's pretty small potatoes these days (and it's only a *default*, so you could always override that if you really cared, and didn't need the compatibility).
- Kevin
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