thanks for your advice.
I investigate this way with another 'stollen' SAN C wich was in preprod on another customer.
I even manage to move both disk 3 and 4. as a result I obtained 1,73To free space on the SAN A.
I launched the consolidate process with a modified COW Heap size 256.
Suspense...
Just one more thought do you think it's possible to consolidate disk one by one instead of all of them together ? I look for command line but didn't find anything probant.
and another one as I invectigate the storage.
there 's some (sesparse)vmdk. of the two disk wich have not moved with the other. I deduced that these ones are orphaned and should be safely deleted ?