RAID disks, errors, etc.
I have an ATTO controlled RAID 6 (8 drives). When it discovers a volume (disk) with a bad sector, the management app notifies me, and warns it may be going to fail soon. I can keep working. I’ve apparently lost no data, but I will keep getting the messages continuously until I put in a fresh drive and let the RAID rebuild.
I’ve read up on bad sectors and how to fix them on Mac OS – erase the drive using one of the security modes that writes zeros over the entire disk. During the process, bad sectors are mapped and skipped by the OS.
So, my questions are:
1. Once I’ve removed a drive with a bad sector from my RAID, and reformatted it to map out the bad sectors, what happens if I use that as a replacement disk the next time ATTO tells me I have a disk with errors?
2. When I replace a drive in my RAID, I don’t format it first. I take it from the packaging, put it in the RAID, tell the control app that’s a new volume for the RAID, and it starts rebuilding itself. So, is the fact I mapped out the bad sectors in Disk Utility ignored by the ATTO Control? Or, does it somehow “know” that a bad sector has been mapped out? I’m thinking not, but I’m not an expert at this.
I can use the reformatted former RAID disks for single disk backups or whatever. But, once disks start failing in a RAID (naturally, after the warranties expire), seems like it’s a matter of time before they all fail. I’m on my third replacement for this particular group of drives, which means I have three 12 TB disks that are functional, but may not be suitable to put back in my RAID.