Hello all,

 

I've been getting a read error on 1 of my Data Disks.

 

On all 3 drives (Parity + 2 Data) an extended SMART test has been preformed and both Parity and Data disks show the read error.

The data disk is currently in a disabled state and the other passed the test and is operational.

There are also 3 cache drives which don't present any error.

 

Important data has been backup to another system and i've ordered 2 replacement disks.

Now my questions is if this is a failing drive or potentially false positive due to bad cables.

Hoping someone can point me in the right direction as i want to start replacing the bad disk today but not sure if it will work when the parity drive throws in a read error.

Is the read error on the parity drive coming from the disabled disk or is that disk also dying.

And if so how would i recover the data when the parity drive is also dying.

 

Should i be follow the guide below to start the rebuild of the potentially dying drive or are the other steps i should take first.

Data Recovery

 

Attached is the syslog and SMART results of the 3 drives.

Thanks for having a look at my issue.

 

 

syslog.txt ST4000LM024-2AN17V_WCK4KPLE-20230209-1212 parity (sdb).txt ST4000LM024-2AN17V_WFF16ZDR-20230209-1212 disk1 (sdc) - DISK_DSBL.txt ST4000LM024-2AN17V_WFF17DZJ-20230209-1212 disk2 (sdd).txt

Disks that fail a SMART test should be replaced.

Just wanted to double check the next steps

 

I start by unassigning the data drive.

Shutdown and replace the drive. 

Start Unraid, preclear and assign the new drive to the parity slot.

Assign the old parity drive to the data drives slot that is currently in a disable state

This should show blue indicators and a copy buttons should become visible.

 

Once the new parity drive is in place i can repeat the process for the data drive?

Unassign, shutdown, replace, start and assign in order for it to rebuild?

Edited February 9, 20233 yr by Joop

Parity swap if for a different scenario, parity copy would likely fail and also you don't want old parity as a data disk, since it's failing.

 

You can replace the disabled disk first, then replace parity, or the other way around, there will probably be some read errors but since there are two bad disks with single parity not many other options.