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mirror broken after doing replace test

Mrdexp

Newbie
Joined
Feb 16, 2021
Messages
2
Hi All,

First of all I'm new to freenas.

I'd be quite honest I don't know what I did exactly to mess things up. I had configured the following:-

-2 x 8TB drives (Pool mirror 1)
-2 x 500GB drives (Pool mirror 2)

my aim was to remove one of the drives from the mirror, clear the data on that drive (using windows diskpart) insert the disk back into the mirror
and the data restored from the other drive.

my first mistake was to test on 8TB drives. which take forever to test on if you have lots of data on them.
I ended up with one disk and no mirror and no way to get the data back onto the disk i removed without actually blowing away and creating a new pool again
which meant i had to copy the data from the freenas server to a 8tb usb drive, then recreate mirror (new pool) and copy the data back again.

Incase anyone tempts fate and to help others, I ended up doing the following which worked:-

1. offline one of the hdd's ( you can findout which drive, by the label on the front of the physical drive to the label under the disks section in freenas server)

2. power down the hdd caddy, if you don't have this feature, power down the freenas server

3. remove the hdd that you offline in step 1. (use a usb interface hook it up to windows and use diskpart in cmd prompt to wipe the disk) refer:-
https://www.seagate.com/au/en/support/kb/troubleshooting-gpt-protective-partition-issues-207837en/

4. insert the disk back into caddy, power on the caddy or server, if you try to online the disk it will be in unavailable status, but still in the mirror, which is a good sign:-refer unavailable_but_still_in_mirror.PNG

5. the hdd you have inserted should be in offline mode status in the pool, click on the drive and select replace, and choose the other drive in the mirror.:-
refer drive_back_online_and_resilver.PNG

I have attached couple of screenshots of the process
 

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Mrdexp

Newbie
Joined
Feb 16, 2021
Messages
2
There's no edit function in previous post, noticed i could have said things better:-

1. offline one of the hdd's ( you can findout which drive, by the serial label on the front of the physical drive and compare it to the serial label under the 'storage--->disks' section in freenas server gui) refer storage_disks.png

2. power down the hdd caddy, if you don't have this feature, power down the freenas server

3. remove the hdd and use a usb interface on the hdd and connect it up to windows pc and use diskpart from cmd prompt to wipe the disk. refer diskpart here:-
https://www.seagate.com/au/en/support/kb/troubleshooting-gpt-protective-partition-issues-207837en/

4. once hdd is wiped insert the hdd on freenas server, power on the caddy or freenas server, once up, if you online the hdd it will go into 'unavailable' status, but still in the mirror, which is a good sign:-refer unavailable_but_still_in_mirror.PNG

5. switch the hdd back to offline if not already done so, now click on hdd again and select replace, and choose the other drive in the mirror.:-
refer drive_back_online_and_resilver.PNG

resilvering will commence on the replacement hdd, once this starts the hdd will automatically go online

once resilvering completes, you can then test file access on each drive by enabling offline. note it will only let you offline 1 drive if you have 2
in a pool mirror. If you have more than 2, one will always be online.
 

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