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When the pool is degraded

If TrueNAS shows the storage pool as DEGRADED, FAULTED, or a drive as OFFLINE / REMOVED, stop normal homelab use and read this page before touching hardware.

The pool is RAIDZ1 — it can survive one drive failure. Losing a second drive before rebuild finishes means permanent data loss for everything on the NAS: media, photos, app configs, backups.

Reference: Backups and pool health.

STOP — do this first

  1. Do not panic-delete files to "free space" — that does not fix a failed disk.
  2. Do not pull any drive until you know which slot serial matches the failed disk in the UI.
  3. Do not create a new pool, destroy the pool, or format disks.
  4. Do not run disk wipe utilities on NAS drives.
  5. Pause heavy writes — stop qBittorrent imports, bulk photo uploads, large copies to A:.
  6. Tell someone if you are not confident — wrong-disk replacement is worse than waiting.

Recognise the problem

  1. Open dsm.saxobroko.com.
  2. Dashboard or Storage → pool status.
  3. Look for:
  4. Pool: DEGRADED (yellow/warning)
  5. One disk: FAULTED, OFFLINE, or UNAVAIL
  6. Open Alerts — note timestamps and disk serial numbers.

Write down:

  • Failed drive serial number
  • Bay/slot number shown in UI
  • Whether resilver is already in progress

While the pool is degraded (still one disk failed)

Do Do not
Keep the NAS powered on Power-cycle repeatedly "to fix it"
Let resilver run if already started Pull "the noisy drive" without checking serial
Use Jellyfin lightly if needed Start massive new downloads
Monitor progress in UI Assume cloud backup exists without checking — TODO: confirm off-site backup in SaxDocs

Performance will be slow until the pool is healthy again.

Replace a failed drive (single disk failure)

Only when you have a replacement drive (same size or larger — 16 TB class):

  1. Confirm in UI which physical drive failed — serial and slot.
  2. If the NAS supports hot-swap for that bay, you may replace without full shutdown — otherwise power down safely via TrueNAS Shut Down.
  3. Replace only the failed drive — match the slot from step 1.
  4. Power on if you shut down.
  5. TrueNAS should detect the new disk and start resilver (rebuild parity).
  6. Wait — resilver on multi-TB pools can take 24+ hours. Do not interrupt.
  7. When complete, pool should return to ONLINE.
  8. Run Run a pool scrub.
  9. Check Read SMART disk errors on the new disk.

If the UI does not start resilver automatically, use Storage → pool → Replace / Manage Disk — exact menu depends on TrueNAS version. Do not guess; screenshot the UI and ask for help.

If TWO drives failed

RAIDZ1 cannot recover the pool. Data on the pool is lost unless:

  • An off-site backup exists (external drive, cloud copy — document status in SaxDocs), or
  • A professional data recovery service is engaged (expensive, not guaranteed).

Do not run zfs destroy or rebuild the pool hoping it comes back

That makes recovery harder. Power off if clicking further, photograph the UI, get expert help.

After the pool is healthy again

  1. Manual scrub — zero errors.
  2. Review what caused failure — age, heat, SMART warnings missed.
  3. Ensure SMART tests are scheduled — Read SMART disk errors.
  4. Update SaxDocs if hardware changed.

Get help

Resource Use
TrueNAS forums / iXsystems docs Resilver stuck, replace wizard
Another technical family member Second pair of eyes before pull
This docs site Server how-to index, External how-to

Ryan inherits the tech per the will — learning these steps is expected, but two-drive failure and pool destroy scenarios warrant outside help.