SOLVED Convert a mirror stripe into a single drive stripe

[level1702]

Hello everyone,

A week ago, I got an alert saying that a few sector we're unreadable (pending). So I bought a new drive and converted my single drive pool to a mirror one with both my faulty and new drive. The problem is that I'm not planning to buy a second drive so I want to remove the faulty drive to see if a complete wipe of the disk could do anything good and if it doesn't, I want to be able to switch my pool to a single drive one so that FreeNAS stop spamming me with error message and that I can use the faulty drive for testing purposes.

I apologize for my bad english.

Thank you for your anwsers

 

[zambanini]

not possible, you need to destroy your pool

 

[Stux]

It is possible. You use the command line to detach the disk/partition in question.

Whether this is advisable is a different thing

 

[Patrick M. Hausen]

Parts of mirror vdevs can be detached as Stux wrote:

Code:

root@freenas-pmh:~ # zpool status ssd
  pool: ssd
 state: ONLINE
  scan: scrub repaired 0 in 0 days 00:01:57 with 0 errors on Sun May  6 13:27:34 2018
config:

	NAME											STATE	 READ WRITE CKSUM
	ssd											 ONLINE	   0	 0	 0
	  mirror-0									  ONLINE	   0	 0	 0
		gptid/19c3909e-4272-11e8-a1f7-0cc47afa3c72  ONLINE	   0	 0	 0
		gptid/f7c524b9-5111-11e8-8cd2-0cc47afa3c72  ONLINE	   0	 0	 0

errors: No known data errors
root@freenas-pmh:~ # zpool offline ssd gptid/f7c524b9-5111-11e8-8cd2-0cc47afa3c72
root@freenas-pmh:~ # zpool detach ssd gptid/f7c524b9-5111-11e8-8cd2-0cc47afa3c72

Not that I would do that to my pool ;)

HTH,
Patrick

 

[level1702]

Ok thank you for your anwsers ! But why exactly is it not a good idea (outside of the fact that I will remove the redundancy of my pool) ?

 

[Patrick M. Hausen]

Precisely because you don't have any redundancy. Hardware is out to get you. ZFS protects you against bad hardware ...

Patrick

 

[level1702]

Sorry to unburry this death thread but I'm not able to offline my drive (which is now removed from the NAS by the way).

Code:

root@NAS:~ # zpool offline NAS 2360576371682270326
cannot offline 2360576371682270326: no valid replicas

 

[Stux]

Think you'll find you can't offline the drive, because its "REMOVED". As can be witnessed by you not having a gptid for it.

 

[Patrick M. Hausen]

In other words: it is offline, already - try to detach or remove it.

Patrick

 

[level1702]

So after a little bit of testing with and without the faulty hard drive and here are the results

(With HDD)

Code:

root@NAS:~ # zpool offline NAS /dev/gptid/64c55dff-ebb9-11e5-812c-001fd08e5c4f
cannot offline /dev/gptid/64c55dff-ebb9-11e5-812c-001fd08e5c4f: no valid replicas

root@NAS:~ # zpool detach NAS /dev/gptid/64c55dff-ebb9-11e5-812c-001fd08e5c4f
cannot detach /dev/gptid/64c55dff-ebb9-11e5-812c-001fd08e5c4f: no valid replicas

root@NAS:~ # zpool remove NAS /dev/gptid/64c55dff-ebb9-11e5-812c-001fd08e5c4f
cannot remove /dev/gptid/64c55dff-ebb9-11e5-812c-001fd08e5c4f: only inactive hot spares, cache, top-level, or log devices can be removed

(Without HDD)

Code:

root@NAS:~ # zpool offline NAS 2360576371682270326
cannot offline 2360576371682270326: no valid replicas

root@NAS:~ # zpool detach NAS 2360576371682270326
cannot detach 2360576371682270326: no valid replicas

root@NAS:~ # zpool remove NAS 2360576371682270326
cannot remove 2360576371682270326: only inactive hot spares, cache, top-level, or log devices can be removed

So any of that seems to work. Do you have other ideas?

 

[Patrick M. Hausen]

Hmm ...

• insert disk
• zpool replace
• zpool offline
• zpool detach
• remove disk

Good luck.
Patrick

 

[danb35]

It really would be helpful to see what's actually going on with your pool--what's the output of zpool status?

 

[level1702]

Hmm ...

• insert disk
• zpool replace
• zpool offline
• zpool detach
• remove disk

Good luck.
Patrick

What do you mean by "zpool replace", you want me to put the faulty drive in as a new drive ?

 

[level1702]

Here is what zpool satus is giving me for this pool

Code:

root@NAS:~ # zpool status NAS
		NAME											STATE	 READ WRITE CKSUM
		NAS											 ONLINE	   0	 0	 0
		  mirror-0									  ONLINE	   0	 0	 0
			gptid/64c55dff-ebb9-11e5-812c-001fd08e5c4f  ONLINE	   0	 0	 7
			gptid/029bf372-4e21-11e8-af61-001fd08e5c4f  ONLINE	   0	 0	 0  (resilvering)

errors: 1 data errors, use '-v' for a list

 

[danb35]

cannot detach /dev/gptid/64c55dff-ebb9-11e5-812c-001fd08e5c4f: no valid replicas

So the problem is that the other disk is resilvering. Once that finishes, you should be able to complete this.

 

[level1702]

So the problem is that the other disk is resilvering. Once that finishes, you should be able to complete this.

No, I tried again after the resielvering completed and it anwsered exaclty the same thing.

 

[danb35]

What is the current zpool status?

 

[level1702]

Code:

root@NAS:~ # zpool status NAS
  pool: NAS
 state: ONLINE
status: One or more devices has experienced an error resulting in data
		corruption.  Applications may be affected.
action: Restore the file in question if possible.  Otherwise restore the
		entire pool from backup.
   see: http://illumos.org/msg/ZFS-8000-8A
  scan: resilvered 2.37T in 0 days 08:34:58 with 9 errors on Fri Jul 27 20:40:32 2018
config:

		NAME											STATE	 READ WRITE CKSUM
		NAS											 ONLINE	   0	 0	 9
		  mirror-0									  ONLINE	   0	 0	18
			gptid/64c55dff-ebb9-11e5-812c-001fd08e5c4f  ONLINE	   0	 0	18
			gptid/029bf372-4e21-11e8-af61-001fd08e5c4f  ONLINE	   0	 0	18

errors: 1 data errors, use '-v' for a list

 

[danb35]

...and

Code:

zpool detach NAS gptid/64c55dff-ebb9-11e5-812c-001fd08e5c4f

doesn't work?

 

[level1702]

Code:

root@NAS:~ # zpool detach NAS gptid/64c55dff-ebb9-11e5-812c-001fd08e5c4f
cannot detach gptid/64c55dff-ebb9-11e5-812c-001fd08e5c4f: no valid replicas

No