SOLVED correct way to remove mirrored SLOG and L2ARC

[Herr_Merlin]

Hi all,

as I am rebuilding the system. I would like to remove the mirrored slogs from the current pool as well as the l2arc. without destroying the pool. in this case I save myself a week of copying data to another external box and copy it back.

What is the correct way to do so?
I did not find an option within the UI, so I assume CLI will be needed?
As I don't want to do a mistakes I am asking here.

 

[HoneyBadger]

I assume that the UI option described here doesn't work?

9. Storage — FreeNAS®11.2-U6 User Guide Table of Contents

www.ixsystems.com

9.2.4. Removing Cache or Log Devices
Cache or log devices can be removed by going to Storage ➞ Pools. Choose the desired pool and click  (Settings) ➞ Status. Choose the log or cache device to remove, then click  (Options) ➞ Remove.

For the mirrored SLOG you might have to select the log-mirror vdev itself to remove it. The L2ARC should be removable without any trouble (and I'm assuming it isn't mirrored)

Failing that, please show the output of zpool status -v for the pool in question and we can find the correct CLI command (it should be zpool remove poolname log-mirror-vdev-name)

 

[Herr_Merlin]

So, based on that output it should be:

for the SLOG - is that correct?

Code:

zpool remove RAIDZ2x2 mirror-2

The L2ARC I removed from the UI. But for the SLOG it only offers me to remove the individual drives of that mirror not the mirror itself.

Code:

root@Certainty:~ # zpool status -v
  pool: RAIDZ2x2
state: ONLINE
  scan: none requested
config:

        NAME                                            STATE     READ WRITE CKSUM
        RAIDZ2x2                                        ONLINE       0     0     0
          raidz2-0                                      ONLINE       0     0     0
            gptid/ad113324-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/b70ef692-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/b9319934-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/c36d135b-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/c580b720-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/c7211f87-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/c910fcf3-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/cacbc915-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/cc946d00-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/ce2a9640-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
          raidz2-1                                      ONLINE       0     0     0
            gptid/d83091b6-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/e25b743f-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/ec623141-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/f668a6d3-e575-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/005cc1c5-e576-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/0a9a05cb-e576-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/14999040-e576-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/1e9518a8-e576-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/288da20c-e576-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/32a727ef-e576-11e9-900e-101f742b8a80  ONLINE       0     0     0
        logs
          mirror-2                                      ONLINE       0     0     0
            gptid/3518514c-e576-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/3660cbc6-e576-11e9-900e-101f742b8a80  ONLINE       0     0     0
        cache
          gptid/33f0d60c-e576-11e9-900e-101f742b8a80    ONLINE       0     0     0
        spares
          gptid/383e6d17-e576-11e9-900e-101f742b8a80    AVAIL

errors: No known data errors

  pool: RG2_ZFS
state: ONLINE
  scan: none requested
config:

        NAME                                            STATE     READ WRITE CKSUM
        RG2_ZFS                                         ONLINE       0     0     0
          mirror-0                                      ONLINE       0     0     0
            gptid/803a51b9-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/83e6b517-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
          mirror-1                                      ONLINE       0     0     0
            gptid/87198e3e-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/8a255bdd-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
          mirror-2                                      ONLINE       0     0     0
            gptid/8d586f2d-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/90748676-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
          mirror-3                                      ONLINE       0     0     0
            gptid/9412bcfe-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/973335c4-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
          mirror-4                                      ONLINE       0     0     0
            gptid/9a9056d4-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/9d99d309-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
          mirror-5                                      ONLINE       0     0     0
            gptid/a0cf2041-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/a4716bdc-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
          mirror-6                                      ONLINE       0     0     0
            gptid/a7a01595-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/aab08d0a-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
          mirror-7                                      ONLINE       0     0     0
            gptid/adf80af9-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/b113b6a7-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
          mirror-8                                      ONLINE       0     0     0
            gptid/b4c463b9-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/b7d5be26-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
          mirror-9                                      ONLINE       0     0     0
            gptid/bb1a162b-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/be2d2790-fafd-11e9-900e-101f742b8a80  ONLINE       0     0     0

errors: No known data errors

  pool: freenas-boot
state: ONLINE
  scan: scrub repaired 0 in 0 days 00:01:35 with 0 errors on Mon Oct 28 03:46:36 2019
config:

        NAME        STATE     READ WRITE CKSUM
        freenas-boot  ONLINE       0     0     0
          da34p2    ONLINE       0     0     0

errors: No known data errors

 

[HoneyBadger]

So, based on that output it should be:

for the SLOG - is that correct?

Code:

zpool remove RAIDZ2x2 mirror-2

The L2ARC I removed from the UI. But for the SLOG it only offers me to remove the individual drives of that mirror not the mirror itself.

Code:

root@Certainty:~ # zpool status -v
  pool: RAIDZ2x2
state: ONLINE
  scan: none requested
config:

        NAME                                            STATE     READ WRITE CKSUM
        RAIDZ2x2                                        ONLINE       0     0     0
          raidz2-0                                      ONLINE       0     0     0
            ...
          raidz2-1                                      ONLINE       0     0     0
            ...
        logs
          mirror-2                                      ONLINE       0     0     0
            gptid/3518514c-e576-11e9-900e-101f742b8a80  ONLINE       0     0     0
            gptid/3660cbc6-e576-11e9-900e-101f742b8a80  ONLINE       0     0     0
        cache
          gptid/33f0d60c-e576-11e9-900e-101f742b8a80    ONLINE       0     0     0
        spares
          gptid/383e6d17-e576-11e9-900e-101f742b8a80    AVAIL

errors: No known data errors

That should give you the desired result here. Note that if you have an active sync write workload, your throughput/latency will be adversely affected when the SLOG mirror is removed.

 

[Herr_Merlin]

worked out fine