On 12/19/07, Michal Soltys <[EMAIL PROTECTED]> wrote:
> Justin Piszcz wrote:
> >
> > Or is there a better way to do this, does parted handle this situation
> > better?
> >
> > What is the best (and correct) way to calculate stripe-alignment on the
> > RAID5 device itself?
> >
> >
> > Does this also apply to Linux/SW RAID5?  Or are there any caveats that
> > are not taken into account since it is based in SW vs. HW?
> >
> > ---
> In case of SW or HW raid, when you place raid aware filesystem directly on
> it, I don't see any potential poblems
> Also, if md's superblock version/placement actually mattered, it'd be pretty
> strange. The space available for actual use - be it partitions or filesystem
> directly - should be always nicely aligned. I don't know that for sure though.
> If you use SW partitionable raid, or HW raid with partitions, then you would
> have to align it on a chunk boundary manually. Any selfrespecting os
> shouldn't complain a partition doesn't start on cylinder boundary these
> days. LVM can complicate life a bit too - if you want it's volumes to be
> chunk-aligned.

That, for me, is the next question - how can one educate LVM about the
underlying block device such that logical volumes carved out of that
space align properly - many of us have experienced 30% (or so)
performance losses for the convenience of LVM (and mighty convenient
it is).

To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to