Hi Mosa3lyan,

Welcome to EMC Community.

For your first statement this may not be the case if VP allocation by FAST policy is enabled.

For your question about new writes, I need more clarifications to give you the right answer..

HTH
-Mohammed Salem

thx Salem

so for FAST-VP

for a new write that will allocate new extents , where these new extents will be allocated (on original Thin Pool  where the tdev is bounded ) or where ?

and for

overwriting an extents that already allocated and promoted to different thin pool than the thin pool where the tdevv where bounded ,?

thanks John

so FAST-VP will improve read and write not only read

thx again

Read miss gives the highest scores to read miss for FAST VP promotion, but back-end write activity will also increase scores for promotion with FAST VP.