Hi Khalid,
1. Is it a concern if a disk shelf is not fully populated.
Empty disk slots are absolutely ok as customer buy disks based on their requirements and budget. We have customers who populate disk shelf half and subsequently buy when they required.
May i know what disk shelf in question here as per your query of 40 DIsks Missing i think it is either DS4486 (48 disks per shelf) or DS460C (60 disks per shelf).
2. Is there be any impact(ex: performance impact or environmental )
What you have is what you get, I mean if you have 8 disks in an aggregate you will get desired performance of 8 disks. Definetly more spindle more performance
Ex:- If i deploy an application on a aggregate of 8 disks vs a disk of 29 disks definetly 29 disks is faster as more disks for your READ and WRITE operations.
Thanks
Nayab