NAS RAID 1 performance and free space percentage

Hi,

We have a RR4312x0 using Flex raid. Two of the disks are RAID 1. The logs report that they are below 20% free and therefore performacnce will degrade.

What is the safe percentage level?

This RAID 1 volume is home to an iSCSI LUN so I was hoping to use its entire capacity for the LUN. If I need to reduce the LUN size then so be it but I'd love to know how much space of a 2TB volume I can give to it.

Also, can I tie an iSCSI LUN/group to access from only 2 calling IP addresses? We have a WIndows Hyper V HOST that is direct connected via the SFP+ ports. This windows iSCSI initiator HOST is also on the same LAN as the 1Gb LAN ports that the business devices connected to the NAS SMB shares via. I need to stop this as it could potentially slow the link down. The iSCSI LUN holds Virtual server VHDs so speed is crucial.

Cheers

Andy

Thanks,

Andy.