On 21/11/16 14:07, Phil Turmel wrote:
On 11/20/2016 09:48 AM, Wols Lists wrote:
On 20/11/16 00:27, Phil Turmel wrote:
Yes. But the new stripes lay on top of the old stripes, unless you move
the data offset. Which is why a backup file holds the old stripe just
in case. If you can move the offset, you use the lower offset for the
lower addresses in the array, and the higher offset for the higher
addresses, on either side of the reshape position.
Okay, understood. So v0.9 and v1.0 always need a backup for a reshape.
Having looked at the man page, this now seems obvious - the superblock
is at the end, so the data offset is 0. But for a 1.0 array, could we
create a data offset?
(So, if we created a data offset, we could then move the superblock and
convert a 1.0 to 1.1 or 1.2? Okay, it can't do it now, but it looks to
me like it shouldn't be that hard ... ?)
But if we have a data offset with v1.2, a reshape will use that space if
it can rather than needing a backup file?
I'm guessing that 1.0 and 1.1 defaulted to no data offset to speak of?
And if we (can) create a decent data offset, we can then use that in
exactly the same way as with v1.2?
Cheers,
Wol
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