RedeyeJay,   Was drive 6 able to rebuild successfully, is the OS and data accessable? Normally a bad drive won't halt the server, as it appears it did in this case. Would you verify if the server is up to date on BIO, iDrac, and the raid controller?
Hello and thanks in advance for any help and suggestions. I've got a PE-T620 With CentOS on a 500GB (4PD) RAID1 array and 10TB storage (4PD) RAID 10 array. The last disk on my storage array was flashing amber. The PERC utility showed SMART errors were present, all info about amber flashing said predictive failure, and processes that involved moving large packets of data were extremely slower than usual. The 4 drives in my RAID10 array are WL5000GSA6454 (5TB SATA III). I misplaced the spare I had in my IT closet so I shopped all over not finding a 5TB SATA / NAS drive that could be delivered anytime in this century. I ended up getting a 6TB thinking it will rebuild the array using 5TB and I'd waste 1TB but at least the array would be healthy and we'd recover lost performance. When the drive arrived, I was unsure about hot swap-ability so I went into the PERC utility to see if I could force the drive offline. There was an option but the warning message said doing so would ruin my array. The other option was "replace member", when I chose it, the message said, "No spare configured". Since all my bays are in use, I can't configure a spare. I ended up turning the server off, replacing the drive, and booting back up. No lights on the new drive carriage during boot or otherwise. I went back into PERC and it just says MISSING DISK. I put the old drive in, still says MISSING DISK. I don't see any option to add a new disk, initialize the new disk, or do anything that seems conducive. The data on that RAID10 array is mission critical. We have online backups but I'd much rather just get the array rebuilt with this new drive if possible. Either I'm missing some setting or option to get the drive going, or I have to get the same drive as the other 3 in the array. My experience with RAID says as long as the drive is equal or larger than the other members it can be used, but if it's bigger, we'll only be able to utilize as much space as the smallest member in the array. Right now the OS is bootable with that 4th PD missing but I have it off because I'm scared something may happen that will result in data loss or worse. Any help would be greatly appreciated!  
PERC H710P - RAID10 - Drive Replacement Issues