So recently I believe I completely destroyed more than half of my hard drives on the array by plugging in a molex connector the wrong way (didn't realize that 4-pin molex was keyed). You can read about all my woes and the heartache with the loss of 6 years worth of media over here : http://lime-technology.com/forum/index.php?topic=32269.0

 

I'm slowly getting my act together. I got the Norco 4220 chassis that I was using finally running. I tested the backplanes and 4 out of the 5 backplanes work flawlessly. The PSU seems to be powering the backplane and the remaining hard drives properly (now that I got the polarity of the molex correct).

 

I assembled everything with the 3 hard drives that survived the burnout and started the server. unRaid booted properly it seems, hard drives were recognized by the BIOS. When I logged into the unraid server management console -- It pains me to see that unraid recognized the slots previously allocated to the 3 surviving hard drives, but listed the 5 hard drives that were fried as "missing". I dared not start the array out of fear that it will start rebuilding parity. My fried hard drives are being serviced to see if a PCB swap would do the trick.

 

The reason I am posting here is to see if anyone knows of a trick by which I can read the data on the drives attached. I'm a Linux newbie, and I remember when the array used to work I could go to /mnt and there I would see the disks listed as disk1, disk2, disk3 etc.

 

However, now after unraid command prompt is reached, when I go to the /mnt folder it is empty.

 

The hard drives are clearly active since unraid recognizes them, and if I do

 

> dmesg|grep SATA|grep link

 

I get a listing of all of the drives with link showing as "up".

 

I'd like to just verify that some of the data in those drives are still preserved. I'd appreciate any input.

 

You could just put your flash drive aside with all of its configuration intact and install unRAID on a new flash with no configuration, boot it up, assign the drives, start the array, and you should be able to access them if they are OK. If one of the drives is the parity drive then set it aside also. Since you only have 3 drives in this scenario you can just run the free version.

 

Yes, one of the drives is the parity drive, and unfortunately it is 4TB (call it "/dev/sda"). The other two drives that survived are 2 TB each (call it "dev/sdb, /dev/sdc"). But if I do what you suggest, wouldn't unraid try to assign one of my data drives (/sdb or /sdc) as the parity drive and overwrite the data? In other words, can I start an array WITHOUT assigning a parity drive, even with the free version of unraid?

wouldn't unraid try to assign one of my data drives (/sdb or /sdc) as the parity drive and overwrite the data?

No. Unraid will never assign drives by itself on a new configuration. Each drive slot selection must be done manually. As long as you do not assign a drive to the parity slot, you will be fine.