Nathan Scott a écrit, le Tue 04 Jul 2006 à 10:14:51AM :
> On Mon, Jul 03, 2006 at 07:18:26PM +0200, Pascal GREGIS wrote:
> > The problem is that I didn't find any explanation on how to determine
> > the values to assign to sunit and swidth. So I am in the incapacity to
> > test my XFS with values for sunit and swidth that make any sense.
> Did mkfs.xfs(8) not help? Also search the list archive, this has
> come up and been answered before, by Dave most recently. I guess
> this is getting pretty close to requiring a FAQ entry, if anyone
> has the time... (some diagrams would be good I guess).
Unfortunately, it didn't really answer to my question.
Maybe it's because I don't know enough about RAID arrays.
Well, what I want to know is :
how can I know the value to assign to sunit and swidth?
All I know at this time for my RAID array is that there are 12 disks of 500 GB,
so 11 * 500 GB of usable space (last disk for checksum), and it's not enough to
know which value to set to sunit, it seems that sunit must not be equal to the
size of one of the disk in my RAID array.
I heard here and there about chunk size and stripe size. But I don't know what
is the cunk size of a RAID array and how can I know it, (it's not me that
bought this RAID array), someone of my company told me that its stripe size was
64k, but are stripe size and chunk size the same? And must sunit be equal to
the chunk size? And swidth?