Extremely slow data rebuild after drive failed

[lovswr]

unRAID v 6.71 - Had a drive fail, so replaced it with a new one.  The rebuild rate is 809 KB/sec or 59 days for an array consisting of 6 4TB drives & 1 parity drive.  I then looked at the log & thought my Parity drive was also failing.  However, after looking through the forums here, I have concluded that I have no idea what is wrong.  So I have included my diagnostics.  Thanks in advance.valhalla-diagnostics-20191205-2244.zip

 

 

[itimpi]

Looks like you are getting continual resets on disk1, although I have no idea of the cause.

[lovswr]

2 hours ago, itimpi said:

Looks like you are getting continual resets on disk1, although I have no idea of the cause.

So, itimpi since you gave me direction to investigate, this is what i did:

 

I have this Mediasonic 4-disc drive bay holding 3 discs, including the aforementioned disk1.  It is vertically orientated & sits at the top of my case.  Just beneath it is a 5-disc drive bay holding 4 discs that is horizontal in nature.  Both are connected to a LSI 8-port controller.  First I shutdown & checked/reseated all SATA connectors & power leads.  Rebooted & I got rebuild speeds of mid 50M for about 15 minutes, then it tricked back down to less than a k & the log showed the same errors as before.

 

 

Shutdown again & completely frogged the SATA cables; that is to say I unplugged the 4 cables from the Mediasonic drive bay & plugged those cables into the other drive bay & vise-versa.  This time I got acceptable speeds for about 30 minutes, then, again, it made its way back to sub 1000 B/sec.  

 

After I thought about this some, I realized that all of my drive failures over the last 2 years or so have come from drives installed in the Mediasonic drive bay.  I have a second Mediasonic bay that I am going to install to see if that is the issue.  I have a Corsair 750W PS which is less than a year old & I believe it sufficient to power 7 SATA drives, one USB jump drive, & about 5 fans.  However, all the drives are essentially coming from one "rail" on the PS so I will have to divvy that up better.  

 

Edited December 6, 2019 by lovswr

[lovswr]

Well this was really bugging me so I kept at it.  I swapped the LSI controller card for the spare I have on hand.  Still the same symptom.  This morning, I took the case apart.  Since my drive bay enclosures are for SATA drives, they have SATA power connectors.  I have a modular PS & I was using MOLEX connectors with MOLEX to SATA adapters.  I removed the adapters & am running SATA cables straight from the PS.  Rebooted & the rebuild is running at about 172.5M/s as I type these words.  I really hope that fixes my problem.

 

 

[JonathanM]

6 hours ago, lovswr said:

Since my drive bay enclosures are for SATA drives, they have SATA power connectors.

Some enclosures have both types of connectors, and you can use whichever style you want and the SATA drives will receive proper power. Essentially those types of enclosures have the power adapters built in. If given a choice, the 4 pin connectors are preferable, as the hardware is much more robust and can carry more current.