Cannot import zpool from old system

j2b

Cadet
Joined
Nov 9, 2019
Messages
3
Hi to all! I’ve got to the place, where I feel, I miss something important. It would be very helpful, if somebody could point me in right direction, or at least explain, why this is happening and what are my chances.

My old FreeNAS 9.x system died due to USB boot failure. I built new system, installed FreeNAS 11.2-U6. After main config and access setup to web ui, I further added 4 2TB WD RED drives from old NAS into new one. Drives were visible by BSD and in UI, SMART gives no errors, thus theoretically I assume, data are intact. But I cannot import pool via Web UI - no pool is listed in drop down.

Turning to CLI for troubleshooting, do not help eather. zpool import gives nothing, not even error. Gpart displays all drives correctly, including 2G swap partition as first, and remaining disk volume as freebsd-zfs partition. Gptid/ folder is populated with drive serials and seems to be correct. But it cannot read labels. I’ve tried zpool import -a and zpool import -d /dev/gptid - no output at all, no pool found. zdb -l /dev/ada0 gives out the following

Code:
# zdb -l /dev/ada0

------------------------------------
LABEL 0
------------------------------------
failed to unpack label 0
------------------------------------
LABEL 1
------------------------------------
failed to unpack label 1
------------------------------------
LABEL 2
------------------------------------
failed to unpack label 2
------------------------------------
LABEL 3
------------------------------------
failed to unpack label 3


From other output, zfs is on adaXp2 partition, but I cannot access it, nor read labels. If I understand situation correctly, if ZFS is not able to read labels, it cannot reconstruct correct zpool. Is this right? How could I read additional information from single drive, regarding former zfs configuration?

Unfortunately, I do not have any notes, nor even remember zpool or volume names from old system, as it died almost a year ago. But I feel, that data are intact, and probably there is a way to recover it, or at least reconstruct manually.

Is there a way to find out names of zpools and zvols from HDD? Or other way, to reconstruct data from these 4x drives?

If it will be so, I’m ready to loose data on these drives. But thought, that this would be the good case, to try and test out, how I could use and learn zfs. But I’m currently stuck with this, and still try to not execute any code, that would kill data on drives completely.

Some knowledge of yours or point to direction of documentation would be very helpful, if this would be the case, to recover data without almost 0 knowedge of former zfs configuration from drives coming from old FreeNAS system, assuming, that new hw may introduce different paths and directories for drives.

Thank you in advance for sharing...
 

j2b

Cadet
Joined
Nov 9, 2019
Messages
3
Here’s an output from gpart show (first drive is where new FreeNAS OS installed.

Code:
=>       40  976773088  nvd0  GPT  (466G)
         40     532480     1  efi  (260M)
     532520  976224256     2  freebsd-zfs  (466G)
  976756776      16352        - free -  (8.0M)

=>        34  3907029101  ada0  GPT  (1.8T)
          34          94        - free -  (47K)
         128     4194304     1  freebsd-swap  (2.0G)
     4194432  3902834696     2  freebsd-zfs  (1.8T)
  3907029128           7        - free -  (3.5K)

=>        34  3907029101  ada1  GPT  (1.8T)
          34          94        - free -  (47K)
         128     4194304     1  freebsd-swap  (2.0G)
     4194432  3902834696     2  freebsd-zfs  (1.8T)
  3907029128           7        - free -  (3.5K)

=>        34  3907029101  ada2  GPT  (1.8T)
          34          94        - free -  (47K)
         128     4194304     1  freebsd-swap  (2.0G)
     4194432  3902834696     2  freebsd-zfs  (1.8T)
  3907029128           7        - free -  (3.5K)

=>        34  3907029101  ada3  GPT  (1.8T)
          34          94        - free -  (47K)
         128     4194304     1  freebsd-swap  (2.0G)
     4194432  3902834696     2  freebsd-zfs  (1.8T)
  3907029128           7        - free -  (3.5K)
 

Heracles

Wizard
Joined
Feb 2, 2018
Messages
1,401
Hey J2b,

If you search in the forum, you will find some posts by @Chris Moore where he offered advice about coming back from too far. When upgrading from a too old version of FreeNAS, he said that some versions should not be skipped and recommended to upgrade to a few specific versions.

Maybe his advice would help you.

Good luck searching for these posts,
 

j2b

Cadet
Joined
Nov 9, 2019
Messages
3
Thank you, @Heracles for quick jump in. Following your suggestion, I assumed, that there could be differences in versions, thus found out a couple of articles, pointing v9.10 to not be skipped. But in my case, I didn't upgrade existing system in terms of OS procedure. I just moved drives to completely new system, including new hardware.

In old NAS system, I had 2 small drives (WD 146GB) without any particular info on them, but decided to test, as they were hanging in system, without use for data storage.

Prior to OS downgrade (or actually fresh install fo v9.10), I plugged in these 2x small drives, and FreeNAS 11.2-U6 UI was able do find zpool on them. And I even managed to import and upgrade it.

This suggests, that OS version would not be a show stopper with former 4x data drives. Am I correct?

When playing with 2x small drives, I noticed strange issue - once small drives were plugged in, FreeNAS GUI Storage > Disks started to show Disk sizes. Once pulled out - remaining 4 data drives do not show Disk size. Not even healthy NVMe drive, which currently holds FreeNAS Boot partition. (No, it's not browser issue, as somebody already has mentioned in forums. I tried different OSes and browsers - all the same.)

I'm keen to dig up some other info, before I try fresh v9.10 with old hw, but currently am skeptical, that this would be the cause. Meanwhile:
- is there a way to read zpool name/ID from single freenas-zfs partition, to at least find out zpool name?
- is it possible to find out zpool configuration from non-working drives? (e.g., to remember, in what configuration they were put)
- is there a possibility to evaluate zfs data health, without loading up zpool (may be data are lost, and I'm just spending time)
- even, if 4x drives would be attached as stripped mirror, ther should be zpool any ways, correct? (as there are freebsd-zfs partition).

Thank you again for shining a light on my case...
 

Heracles

Wizard
Joined
Feb 2, 2018
Messages
1,401
Hi again,

ZFS is pretty complex and if it does not work by itself, it usually means that it can not be forced to. This is why there is no filesystem check and fix tool for ZFS. ZFS will check and fix itself, or nothing will.

Because I never worked with these FreeNAS versions, I will let other give you their own advice. Myself never do this kind of upgrade without an easy way to re-start everything from beginning.

Here, on site, I have 2 of the 3 servers in my signature. When I will decide to go with FreeNAS 12, I will do Thanatos first. Should I destroy everything, so be it. I will re-push from Atlas once Thanatos fixed. Once I trust FreeNAS 12 enough, I will keep Thanatos in sync for a little while and then try the upgrade on Atlas. Should it work, great. Should it fail, I can re-sync from scratch over LAN using Thanatos as a source.

To re-sync Hades would be the hardest to do, so I will do it last, only after I managed to upgrade the 2 others.

In all cases, good luck fixing your own situation,
 
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