If you get this error:
CRITICAL: megacli:[Volumes(2): DISK0.0:Degraded,DISK1.1:Degraded: Devices(4): 06,07,04=Online 05 (WD-WCC1P1090364WDC WD2000FYYZ-01UL1B1 01.01K02)=Unconfigured(bad)]
You need to rebuild the drive. First use smartctl to check if the disk is ok.
Then check which disk is bad with
megacli -pdlist -a0
If the disk for example is this one
... Enclosure Device ID: 252 Slot Number: 0 ...
get full info
megacli -pdinfo -physdrv[252:0] -a0
Steps:
1. Change the state to good
megacli -pdmakegood -physdrv "[252:0]" -a0 Adapter: 0: EnclId-252 SlotId-0 state changed to Unconfigured-Good. Exit Code: 0x00
2. If the following commands shows “Foreign flag” in “Foreign state” you need to clear it with:
megacli -cfgforeign -clear -a0 Foreign configuration 0 is cleared on controller 0.
3. Designate the drive as hotspare
megacli -pdhsp -set -physdrv "[252:0]" -a0 Adapter: 0: Set Physical Drive at EnclId-252 SlotId-0 as Hot Spare Success.
4. The automatic rebuild should now start. Check with
megacli -pdinfo -physdrv[252:0] -a0
... Firmware state: Rebuild ... megacli -pdrbld -showprog -physdrv "[252:0]" -a0 Rebuild Progress on Device at Enclosure 252, Slot 0 Completed 1% in 3 Minutes.
Exit Code: 0x00
Or start the rebuild manually with
megacli -pdrbld –start –physdrv “[252:0]” –a0