We are running our datacenter with one array of RAID 1 (with 2 x 2TB) on a HP XW6600 (CentOS 7).
We'd like to increase disk space and avoid as much as possible downtime while upgrading.
There are currently several solutions:
Switch from RAID 1 to RAID 10. High risk of downtime (or even data loss) since we don't have any server expert in the firm. We don't prefer this solution much.
Keep the current RAID 1 but swap the disk to larger volume. Low risk and less downtime. This seems possibly the one we choose but we waste 2 x 2TB old disks. So the 3rd one appears in the mind.
Keep the current RAID 1 and install another new RAID 1. Is this possible with the current HP server?