docs/Hardware/Storage Node 01 (TrueNAS Core)/Replacing a Drive.md

Purpose

This document acts as a workflow to understand how to replace a drive on TrueNAS Core when it is hosted on an HPE Proliant server with HBA / IT Mode enabled. This enables you to hot-swap drives without rebooting TrueNAS Core.

Offline the Disk

• You will log into the TrueNAS Core WebUI.
• Navigate to "Storage > Disks"
  • Look for the drive that is having issues / faults / unavailable and reference it's da number to reference later. (e.g. da3)
  • Confirm the serial number of the drive and correlate that to the physical location in the Disk Arrays document,
• Navigate to "Storage > Pools"
• Look for the gear icon to the right of the storage pool and click on it
  • Click on "Status"
    • Locate the failing / failed drive and click on the "..." elipsis menu button
    • Proceed to "Offline" the disk. This ensures that TrueNAS Core stops trying to use the disk.

Physical Disk Replacement

At this point, we need to physically go to the server and pull out the failing drive and replace it.

• Take note of the new serial number on the replacement drive and update the Disk Arrays document accordingly.
• Insert the replacement drive back into the TrueNAS Core server

Trigger Disk Re-Scan

Now we need to tell TrueNAS / FreeBSD to re-scan all disks to locate the new one.

• Within the TrueNAS Core WebUI, navigate to "Shell" and run the following command: camcontrol rescan all
• Navigate (back) to "Storage > Pools > Status"
  • Locate the failed drive via it's da number again, and click the "..." elipsis menu button
  • Proceed to "Replace" the disk, and when given a dropdown menu, only the new replacement disk should appear with the same da number

!!! success "Resilvering Started" At this point, TrueNAS core will start taking parity data from the rest of the drives in the storage pool to reconstruct the replaced drive. This may take an hour or two depending on the speed of the drives and used capacity within the pool itself.

It is recommended to run a SCRUB right after resilvering to ensure that all data is accurate and healthy.

!!! info "Checking on Resilvering Process via CLI" If you feel so inclined, you can check on the resilvering process by running the following command: sh zpool status | grep "to go"