Hello. As long as it is not a sliced RAID array(when RAID 1 & RAID 10 do not share the same Physical Disks) as you have indicated, it is fine. Delete RAID 10 and replace the existing drives  then recreate the RAID 10. The RAID 1 array will not be affected in any way. Make sure that you have validated backup of all the data before deleting this RAID array.
Hi guys, I have a PE 2950 3rd gen with perc 6i,  Currently i has 2 raid arrays,   0+1 bays with 2 x 146GB SAS in RAID1 mirror 2+3+4+5 bays with 4 x 300GB SAS in RAID10 I need more space so the RAID10 array needs to go, so i can add 4 x 1TB SATA HDDs in RAID10 again (from 557GB to 2TB) So if i delete the RAID10 array will it affect my first mirror array wich holds the OS ? I never did a thing like this, everytime i started from scratch, removing or upgrading all HDDs..  But now i need to keep the first mirror array, or else its going to be a real PAIN to reinstall the OS and everything it holds.  Waiting for a reply, Cheers, Alex.
upgrading HDDs on one virtual drive array