Lukegao: by freem.ai...

2026-01-23T05:35:10Z

by freem.ai...

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{{DISPLAYTITLE:ZFS Pool Import Issue}}

''This conversation was exported from ChatGPT''<ref>{{cite web|title=ZFS Pool Import Issue|url=https://chatgpt.com/share/6971d533-1acc-800b-a048-a162caba12d7|publisher=ChatGPT|access-date=2026-01-22}}</ref>

== gpt-5-2 ==
=== User: Hi. ===
Hi. I'm on version TrueNAS-SCALE-25.04.2.6. I'm using 8 14tb HDD's in Raidz2. I do have my data backed up so I'm not super panicked, but I need to get to the bottom of this and get things back up and running.

I woke up this morning and server was on but not accessible via web GUI, and no HDMI output, so I had to hard power down. Now, when booting, I'm repeatedly getting stuck at:
"Starting ix-zfs.service - Import ZFS pools...
(1 of 2) Job ix-zfs.service start running (53s / 15min 26s)"

=== Assistant: You’re hitting this during ZFS pool import, which usually means ZFS is struggling with the pool hung I/O, device errors… ===
You’re hitting this during ZFS pool import, which usually means ZFS is struggling with the pool (hung I/O, device errors, or a corrupted import state). The hard power-off likely exposed an existing issue rather than caused it.

The good news:
* Your system is not frozen — ix-zfs.service waits up to 15+ minutes
* RAIDZ2 + backups = very recoverable situation

Below is a safe, structured way to diagnose and recover, starting with the least destructive options.

==== What’s most likely happening ====

One (or more) of these:
# A disk is slow, timing out, or failing
# ZFS import is blocked waiting on a bad drive
# Previous unclean shutdown left the pool in a dirty state
# Hardware issue (HBA, SATA cable, power)

ZFS is conservative — it will wait forever rather than risk corruption.

==== Step 1: Let it try once (important) ====

On the current boot:
* Wait at least 10–15 minutes total
* Watch for any disk activity LEDs

If it eventually proceeds → we move to cleanup.
If it never completes → proceed below.

==== Step 2: Interrupt boot → get shell access ====

Reboot and do this:
# At the GRUB menu, choose: ``<code> Advanced options → TrueNAS SCALE → Recovery Mode </code>`<code> OR press </code>Esc<code> during boot
# Select: </code>`<code> Drop to root shell <syntaxhighlight>
You should now have a console prompt.

==== Step 3: Check if ZFS sees your pool ====

Run:

</syntaxhighlight>bash
zpool import

<syntaxhighlight>
===== Possible outcomes: =====

====== A) Pool is listed normally ======

Example:

</syntaxhighlight>
pool: media
state: ONLINE

<syntaxhighlight>
Good — try importing manually.

====== B) Pool shows DEGRADED / FAULTED ======

This usually points to one or two bad disks (still safe in RAIDZ2).

====== C) Command hangs ======

That strongly indicates a disk that is not responding.

==== Step 4: Try a safe manual import ====

First, try read-only (zero risk):

</syntaxhighlight>bash
zpool import -o readonly=on -f <poolname>

<syntaxhighlight>
If that works → excellent, your data is intact.

If it hangs or fails, try:

</syntaxhighlight>bash
zpool import -f -m <poolname>

<syntaxhighlight>
(-m ignores missing logs/cache devices)

==== Step 5: Identify bad or slow disks ====

Run:

</syntaxhighlight>bash
lsblk -o NAME,SIZE,MODEL,SERIAL

<syntaxhighlight>
Then:

</syntaxhighlight>bash
dmesg | grep -Ei "ata|sas|scsi|error|timeout|reset"

<syntaxhighlight>
You're looking for things like:
* I/O error
* link reset
* device offline
* failed command

⚠️ One bad disk can stall the entire import

==== Step 6: If import still hangs — isolate the offender ====

Since you’re backed up, this is safe.
# Power off
# Disconnect ONE drive
# Boot → try zpool import
# Repeat until import succeeds

RAIDZ2 allows two missing disks, so this is safe for diagnosis.

Once the pool imports, ZFS will clearly tell you which disk(s) are missing or failed.

==== Step 7: After successful boot (VERY IMPORTANT) ====

Once the system boots:

</syntaxhighlight>bash
zpool status -v

<syntaxhighlight>
Then immediately:

</syntaxhighlight>bash
zpool scrub <poolname>

<syntaxhighlight>
Also check SMART:

</syntaxhighlight>bash
smartctl -a /dev/sdX

<syntaxhighlight>
(Replace sdX with the failing drive)

==== Common root causes I see with SCALE 25.x ====

Based on your setup and symptoms:
* SATA cable degradation
* Power splitter failure
* One HDD entering slow-death (timeouts, not total failure)
* HBA firmware issue (LSI cards especially)

Disks that are “half-alive” are the worst for ZFS.

==== What NOT to do (important) ====

❌ Do NOT:
* Reinstall TrueNAS yet
* Destroy or recreate the pool
* Run zpool clear blindly
* Panic — this is a classic ZFS recovery scenario

==== Next step ====

Reply with:
# Output of: </syntaxhighlight>bash zpool import </code>`<code>
# Whether it hangs or lists the pool
# Any error lines from </code>dmesg`

I’ll walk you through the exact recovery path from there.

== References ==
<references />

[[Category:ChatGPT Shares]]
[[Category:openai]]

Openai/6971d533-1acc-800b-a048-a162caba12d7 - Revision history

Lukegao: by freem.ai...