Drive in Pool Shows Replacing and FAULTED, how to fix?

[jkingaround]

Hi all, looking for some help. I recently was getting unreadable sectors on one of my 4tb disks, and ordered a replacement. Since I no longer have any spare bays (using all 24 bays in my chassis) once I got the replacment, I offlined the old disk, shut it down, put the new drive in and hit replace without the usual burn in I did when I had the extra bays. However, something happened while resilvering and it never fully replaced properly. From replies on a reddit thread I was told it was potentially because the WD RED SMR (WD40EFAX) I bought instead of the older CMR version (WD40EFRX) has issues with ZFS/FreeNAS. I have set up a refund and am planning on buying the new (older version) disk as soon as I can get the return dealt with through amazon. However, since my pool is now degraded I would like to put in the old drive that was starting to fail (but the pool wasn't degraded yet) until I can get the new disk popped in there. However, I'm not sure the best way to go about this as I cannot get the drive offline and don't want to risk anything.

What is the best course of action to swap back to the old pre-failing disk? How do I "properly" do a burn in for the replacement without being able to have both disks plugged in at the same time?

Help please.

Server Specs:

Show

CHASSIS: SUPERMICRO 4U 846E16-R1200B
MOBO: X8DTE-F
RAM: 128GB ECC
CPU: Dual Intel XEON L5520
DRIVES: 16 x 4TB WD Red RAID Z2 | 8 x 8TB WD Red RAID Z2

Note the scrub cancelled is actually me stopping the resilvering that tried to happen AGAIN after rebooting to see if that helped anything.

zpool status -v Chico output:

Code:

  pool: Chico
state: DEGRADED
  scan: scrub canceled on Thu Jun 18 21:20:27 2020
config:

    NAME                                              STATE     READ WRITE CKSUM
    Chico                                             DEGRADED     0     0     0
      raidz2-0                                        DEGRADED     0     0     0
        replacing-0                                   UNAVAIL      0     0     5
          7441467098546415565                         UNAVAIL      0     0     0  was /dev/gptid/dbd87bda-d718-11e9-b598-000c2920d667
          gptid/e981831a-aed7-11ea-aa5d-000c2920d667  FAULTED      0   119     0  too many errors
        gptid/de312a5c-d718-11e9-b598-000c2920d667    ONLINE       0     0     0
        gptid/e06a57a6-d718-11e9-b598-000c2920d667    ONLINE       0     0     0
        gptid/e2b9b37c-d718-11e9-b598-000c2920d667    ONLINE       0     0     0
        gptid/e4f9aa44-d718-11e9-b598-000c2920d667    ONLINE       0     0     0
        gptid/e71ecdd5-d718-11e9-b598-000c2920d667    ONLINE       0     0     0
        gptid/e974b0cb-d718-11e9-b598-000c2920d667    ONLINE       0     0     0
        gptid/ebc31519-d718-11e9-b598-000c2920d667    ONLINE       0     0     0

errors: No known data errors