Greggy

I'm trying to understand the sequences of events before and after a disk failure in UnRaid. Just trying to prepare myself. When UnRaid detects a single CRC error, does it just disable the drive? How do I know to replace the drive? Do I just rebuilt it and try again? Or, fire it into the garbage and replace? How do I know when to replace a drive? Do I just rely on the SMART results and my own intuition? I sort of assumed a disk's firmware kept track of good & bad sectors, and raid systems worked behind the scenes shuffling & re-writing files as required. I don't think that's the case? I think it's one CRC error, and the drive is disabled? Just trying to understand, so I know what to do. PS: If this discussion has been discussed before, please send me a link. I'm assuming it has.

Yes, good recommendation... will it boot on another computer? That was my Ahha moment!

I most definitely hate to submit this post. Partly because I'm an UnRaid newbie, but mostly because I'm both an UnRaid and Linux newbie. I had endless problems trying to boot Unraid last week. I wasn't sure if my boot device wasn't selected correctly, or all my USB stick(s) decided to quit on the same day. I wish I had taken better notes, but my belief is the USB Creator has taken on some new updates, that are maybe not so compatible with older systems? Syslinux ? For me anyway, it seemed if I created a USB stick with Rufus specifying Syslinux 4.x, and copied the UnRaid install files over, it would boot for me and install UnRaid. Hope this post helps to point you in the right direction.

I'm an UnRaid newbie as well, so best wait for someone else to post before following any of my advice. Adding a second 8TB parity drive is not going to buy you anything, except a dual redundant 4TB array. (Smallest of the parity drives) I think a logical course of action might be to rebuild disk 4 with an 8TB disk to get you back into safe territory. And then replace your 4TB parity drive with an 8TB drive to expand your storage space. What I don't know is if you can just rebuild the 4TB parity drive with an 8TB. Or, if you may need to perform a New Config with the 8TB parity drive.