Question about redundancy and potentially failing disks...
If I have a softRAID RAID 1 mirrored volume consisting of 2 disks but I have a third disk of the same size which is predicted to potentially fail (but hasn't failed yet), is my data more secure or less secure if I include the potentially failing disk in the array as a third member for extra redundancy? I know having three members for more redundancy is more secure than two so, I guess what I'm really asking is can the faulty disk corrupt the information on the other two healthy disks and am I thus, better off leaving this third disk out until another third healthy disk can be obtained?
Thanks in advance for your help. :)
You are correct, with one cavaet. Some drives fail by hanging the system, or interfering with bus communication. I do not have any data however, to show that a small number of reallocated sectors are correlated with increased chances of this kind of failure.
So if the reallocated sector count is low, and stable, there is probably no risk to having it be a third disk in the mirror. What you can do though, is keep it primarily "off line" and connect it weekly for instance, to rebuild, then remove it again.
Ok, great. :) Thanks for your assistance. Sounds like a perfect solution. :-)