>>>>> "dm" == David Magda <dma...@ee.ryerson.ca> writes:
dm> The other thing is that with the growth of SSDs, if more OS
dm> vendors support "dynamic" sectors, SSD makers can have
dm> different values for the sector size
okay, but if the size of whatever you're talking about is a multiple
of 512, we don't actually need (or, probably, want!) any SCSI sector
size monkeying around. Just establish a minimum write size in the
filesystem, and always write multiple aligned 512-sectors at once
instead.
the 520-byte sectors you mentioned can't be accomodated this way, but
for 4kByte it seems fine.
dm> to allow for performance
dm> changes as the technology evolves. Currently everything is
dm> hard-coded,
XFS is hardcoded. NTFS has settable block size. ZFS has ashift
(almost). ZFS slog is apparently hardcoded though. so, two of those
four are not hardcoded, and the two hardcoded ones are hardcoded to
4kByte.
dm> Until you're in a virtualized environment. I believe that in
dm> the combination of NetApp and VMware, a 64K alignment is best
dm> practice last I head. Similarly with the various stripe widths
dm> available on traditional RAID arrays, it could be advantageous
dm> for the OS/FS to know it.
There is another setting in XFS for RAID stripe size, but I don't know
what it does. It's separate from the (unsettable) XFS block size
setting. so...this 64kByte thing might not be the same thing as what
we're talking about so far...though in terms of aligning partitions
it's the same, I guess.
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