Al313

The problem is at the server drive backplane. I did a workaround and solved the connection problem. My data rebuild is now running at 57-58 MB/sec. Thanks to JorgeB for pointing me in the right direction. I thought I would post the steps I took to narrow down the cause of my problem in case this would be helpful to someone else. Per JorgeB's suggestion, I first swapped the cable for a new one. Problem persisted. Next I removed and reseated the controller and rechecked the connections. Problem persisted. I have three 8 port controllers, and only have 22 drives populated (24 drive server with a hot swap backplane). So next I routed the drive to a different controller that had two open ports. Problem persisted. At that point, I figured the problem could be at the backplane connection. So I decided to place the drive at one of the open slots but first, reconnect the drive to the original controller and original port. Problem Solved! I haven't looked for the specific cause of my intermittent at the backplane connection yet. I'll wait until my data rebuild is complete before I do that. Anyway, that's how I got to the bottom of this problem and I hope this may help someone else.

A few days ago, I had a power outage. System shut down normally (auto UPS). Yesterday I powered up and disk 10 was missing. It appeared that I had a hard drive failure so I installed a new drive and started data-rebuild. I noticed that the system was running slow 1-5 MB/sec. The new drive I had just installed ran for about 15 minutes then failed and unraid halted. I replaced the problem drive with another new drive and restarted data-rebuild. The system seemed to be running fine but the rebuild speed was still very slow, around 1 to 2 MB/sec. I let it run overnight and is now at 20 hours plus and is still running between 1-2 MB/sec with only 2% progress. At this rate, the system is telling me it will take 2 months to finish data rebuild. This is a simple system, just a bunch of disks. Nothing fancy. The system is running version 6.8.2 and has a total of 22 drives ( including 2 parity drives) and the largest disks are 6 TB. This system has been running well for several years. As I recall, the last time I swapped a 2 TB drive with a 6 TB drive the data rebuild took 26-28 hours or so. I just ran diagnostics (while the data rebuild is active) and they are attached to this post. I looked at the dashboard and all seems normal i.e. cpu usage, memory. The only possible issue I could see is disk 5 has a "thumbs down" for smart status. Could disk 5 be the cause of the slowdown? If this is a possibility, would it be better to stop the current data rebuild of disk 10, restart unraid with disk 10 contents emulated, and replace disk 5 and rebuild that drive before going back to fix the disk 10 issue? I would appreciate suggestions on how best to proceed. Thanks. mserver1-diagnostics-20200930-1939.zip