Il 28/04/2014 15:43, Peter Lieven ha scritto:
b) the allocationmap should be allocated even for out-of-range opt_unmap_gran,
using a granularity of 64 sectors in that case.
Would the increase of the resolution bring any benefit? If we increase the
resolution I think all sectors falling into the same
physical cluster would end up with the same status.
What if opt_unmap_gran is 32K or lower? In this case you're not using
an allocationmap.
c) an opt_unmap_gran of 32K should be used by QEMU as a cluster size
Do we have evidence of used cluster sizes on real hardware? I only know our
Equallogic storages which have 30720 sectors.
IDE does not specify the granularity, so an IDE disk will show a
granularity of 1 sector (but it has LBPRZ=0).
d) the threshold should be dynamic and equal to iscsilun->cluster_sectors
I don't think this is useful. For big cluster_sizes we will end up to never use
the allocation cache.
Right.
Paolo
