degraded ZFS mirror

[dominator99]

My Freenas 11 NAS reported a degraded disk in a 2 disk mirror & marked the disk as removed. I offlined & removed the disk & ran Seagate Seatools long scan which found no problems with the disk. I refitted the disk to my NAS & under storage / disks it shows the disk as unused. How can I add this disk back into the Black-tower-M3 mirror?

 

[Alecmascot]

10. Storage — FreeNAS®11.3-U3.2 User Guide Table of Contents

www.ixsystems.com

 

[dominator99]

Sorry, but I've been through the manual & it doesn't help

 

[Alecmascot]

So take us through the steps in the manual to where it does not work for you.

 

[Yorick]

You're not showing us your pool. Since you offlined the disk, you should be able to choose the offlined disk, select Replace (see manual), and then choose the unused disk.

 

[dominator99]

OK, got it, it's now resilvering

 

[dominator99]

still have a problem; the resilver of ada7 was completed but ada8 was offlined! I still can't see from the manual how to add a disk to an existing mirror

 

[dominator99]

The only solution was to export/disconnect ada7 & create a new pool (adding existing pool only gave me the option to import ada7 which, being a single disk, was a stripe not a mirror).
I couldn't find a way to add a disk to a stripe pool to convert it to a mirror pool (maybe it's not possible).
Fortunately this Black-Freenas is a backup of EMC-Freenas!
I still don't know why the original ada7 disk was marked as degraded & offlined when Seagate Seatools could find no problems with the disk

 

[Yorick]

> I couldn't find a way to add a disk to a stripe pool to convert it to a mirror pool

You can certainly add a disk to a single-drive vdev to make it into a mirror vdev. I'm assuming by "stripe pool" you mean a pool made up of single-disk vdevs. Each of those single-disk vdevs can have a mirror attached to it. A single-disk vdev is just a special case of a degraded mirror vdev, as far as ZFS is concerned.

I'm kinda curious myself how the FreeNAS UI handles that, if at all, but that test will need to wait until my current disk burnin is done. A few more days.

I do know you can just do that from command line. Here's an example:

Code:

thorsten@raidz-expand:/etc/depmod.d$ sudo zpool create stripling /home/thorsten/zfile/sparse_disk1 /home/thorsten/zfile/sparse_disk2 /home/thorsten/zfile/sparse_disk3
thorsten@raidz-expand:/etc/depmod.d$ zpool status
  pool: stripling
 state: ONLINE
  scan: none requested
config:

    NAME                                 STATE     READ WRITE CKSUM
    stripling                            ONLINE       0     0     0
      /home/thorsten/zfile/sparse_disk1  ONLINE       0     0     0
      /home/thorsten/zfile/sparse_disk2  ONLINE       0     0     0
      /home/thorsten/zfile/sparse_disk3  ONLINE       0     0     0

errors: No known data errors
thorsten@raidz-expand:/etc/depmod.d$ sudo zpool attach stripling /home/thorsten/zfile/sparse_disk1 /home/thorsten/zfile/sparse_disk4
thorsten@raidz-expand:/etc/depmod.d$ zpool status
  pool: stripling
 state: ONLINE
  scan: resilvered 106K in 0 days 00:00:00 with 0 errors on Tue Jul 21 18:05:00 2020
config:

    NAME                                   STATE     READ WRITE CKSUM
    stripling                              ONLINE       0     0     0
      mirror-0                             ONLINE       0     0     0
        /home/thorsten/zfile/sparse_disk1  ONLINE       0     0     0
        /home/thorsten/zfile/sparse_disk4  ONLINE       0     0     0
      /home/thorsten/zfile/sparse_disk2    ONLINE       0     0     0
      /home/thorsten/zfile/sparse_disk3    ONLINE       0     0     0

errors: No known data errors
thorsten@raidz-expand:/etc/depmod.d$ sudo zpool attach stripling /home/thorsten/zfile/sparse_disk2 /home/thorsten/zfile/sparse_disk5
thorsten@raidz-expand:/etc/depmod.d$ sudo zpool attach stripling /home/thorsten/zfile/sparse_disk3 /home/thorsten/zfile/sparse_disk6
thorsten@raidz-expand:/etc/depmod.d$ zpool status
  pool: stripling
 state: ONLINE
  scan: resilvered 123K in 0 days 00:00:00 with 0 errors on Tue Jul 21 18:05:48 2020
config:

    NAME                                   STATE     READ WRITE CKSUM
    stripling                              ONLINE       0     0     0
      mirror-0                             ONLINE       0     0     0
        /home/thorsten/zfile/sparse_disk1  ONLINE       0     0     0
        /home/thorsten/zfile/sparse_disk4  ONLINE       0     0     0
      mirror-1                             ONLINE       0     0     0
        /home/thorsten/zfile/sparse_disk2  ONLINE       0     0     0
        /home/thorsten/zfile/sparse_disk5  ONLINE       0     0     0
      mirror-2                             ONLINE       0     0     0
        /home/thorsten/zfile/sparse_disk3  ONLINE       0     0     0
        /home/thorsten/zfile/sparse_disk6  ONLINE       0     0     0

errors: No known data errors

 

[Yorick]

I still don't know why the original ada7 disk was marked as degraded & offlined when Seagate Seatools could find no problems with the disk

That is indeed a good question. "Hardware" in some capacity.
Could be any of:
- RAM a little dodgy. Would need to be run through its paces, hard to say without ECC whether errors occured
- SATA cable not great / not seated right. Replacing cable with a high-quality one should eliminate that worry and is quick and easy
- Unlikely but possible: Issues with PSU, motherboard, or CPU

Basically anything and everything that can corrupt data written to the disk, assuming the disk itself is okay.

 

[dominator99]

I'm no coder so am not comfortable using the command line but thanks for the info

 

[Yorick]

"Coder" and "Command Line" are two very different things. CLI isn't scary, I recommend you get familiar with it by using non-destructive commands such as zpool status and zfs-stats -a.

That said, I've had a chance to play around in the UI. In a pool with single-disk vdevs, you can go into the Pool Status, choose "Extend" to the right of the vdev that's not mirrored, choose a disk, and that makes it into a mirror. Easy Peasy.
To revert that, choose one of the disks in a mirror, and "detach" it, making the vdev into a single-disk vdev without parity again.

 

[dominator99]

Now a new problem, the newly created Blacktower M3 mirror is not showing in Windows 10 network (the other Black tower mirrors M1, M2 & M4 are showing). I've checked all 4 disk settings & they appear identical to one another; the only exception being that under sharing/SMB/edit Black-tower-M1, Black-tower-M2 & Black-tower-M4 have (ACL) at the end of their name but Black-tower-M3 doesn't.
Any suggestions would be appreciated

'That said, I've had a chance to play around in the UI. In a pool with single-disk vdevs, you can go into the Pool Status, choose "Extend" to the right of the vdev that's not mirrored, choose a disk, and that makes it into a mirror'

I tried that but didn't get a 'mirror' option it was stuck on 'stripe'

 

[Yorick]

I tried that but didn't get a 'mirror' option it was stuck on 'stripe'

That sounds like you were looking at the pool, not the vdev. You want to add a disk to the individual vdev, not to the pool.

Ars Technica's overview of how pools and vdevs hang together should be helpful. https://arstechnica.com/information...01-understanding-zfs-storage-and-performance/

Now a new problem, the newly created Blacktower M3 mirror is not showing in Windows 10 network

You want a dataset on that mirror, set the dataset's share type to SMB during creation, then set your permissions how you need them. Best practice is to store your data in datasets, not directly on the pool root. I have a walkthrough of how to set up Windows shares, here: https://www.youtube.com/watch?v=9Xsgsap0wgQ

 

[dominator99]

I'm sorry but your video on Windows shares left me 'cold' (I'm 72 & life's too short to delve in depth into new topics)
The new M3 mirror I created in Freenas 11.3 seems fine, it appears Windows 10 is the problem (version 2004) no longer allowing 'guest'. I assume the other 3 mirrors are working because they are 'old', M3 is new to Windows 10 (version 2004) so how do I configure this new 'share@?

 

[Yorick]

no longer allowing 'guest'

Yeah that's been scrubbed from Win10 for security reasons.

All the best with your endeavor!