TrueNAS - Need Help attaching disk in mirror to replace bad disk

I keep getting error of degrading pool and need to replace one of my disk. so as usual, I bought new disk and put in my system. I can see my disk as “da6”.

Here is glabel status:

root@truenas[~]# glabel status
                                      Name  Status  Components
gptid/f5194172-3056-11eb-a6bc-244bfe5763c3     N/A  ada0p1
gptid/f55d0cd8-3056-11eb-a6bc-244bfe5763c3     N/A  ada1p1
gptid/79f3d4a9-463d-11eb-8e4f-244bfe5763c3     N/A  da0p2
gptid/b9c68f19-4645-11eb-8e4f-244bfe5763c3     N/A  da1p2
gptid/bb7ed593-4645-11eb-8e4f-244bfe5763c3     N/A  da2p2
gptid/ba3c69de-4645-11eb-8e4f-244bfe5763c3     N/A  da3p2
gptid/7ab325d7-463d-11eb-8e4f-244bfe5763c3     N/A  da4p2
gptid/b66ee4b0-4645-11eb-8e4f-244bfe5763c3     N/A  da5p2

Here is how zpool status look like:

  pool: MainOne
 state: ONLINE
  scan: scrub repaired 6M in 04:34:02 with 0 errors on Tue Mar  2 17:34:02 2021

	NAME                                            STATE     READ WRITE CKSUM
	MainOne                                         ONLINE       0     0     0
	  mirror-0                                      ONLINE       0     0     0
	    gptid/b9c68f19-4645-11eb-8e4f-244bfe5763c3  ONLINE       0     0     0
	    gptid/bb7ed593-4645-11eb-8e4f-244bfe5763c3  ONLINE       0     0     0
	  mirror-1                                      ONLINE       0     0     0
	    gptid/b66ee4b0-4645-11eb-8e4f-244bfe5763c3  ONLINE       0     0     0
        gptid/ba3c69de-4645-11eb-8e4f-244bfe5763c3  ONLINE       0     0     0

gptid/ba3c69de-4645-11eb-8e4f-244bfe5763c3 to be replaced which is attached as “da3” and other one is “da5” in same mirror set. Currently not showing any error but I get read and write error on “da3”.

Here is set of different command I did to attach disk:

zpool attach MainOne ba3c69de-4645-11eb-8e4f-244bfe5763c3 da6

zpool attach MainOne da5 da6

zpool attach MainOne gptid/ba3c69de-4645-11eb-8e4f-244bfe5763c3 SERIAL NUMBER OF DISK

I keep getting error. I would really appreciate help. Here is example of error:

root@truenas[~]# zpool attach MainOne ba3c69de-4645-11eb-8e4f-244bfe5763c3 da6
cannot attach da6 to ba3c69de-4645-11eb-8e4f-244bfe5763c3: no such device in pool

I have a video on how to replace failed drives here

I am watching as I type this. But how come I can’t do that from CLI.

You should be able to but I don’t have a video for that, try their forums to find that process.

I looked and didn’t find any solid information as I see everyone is using

zpool attach POOLNAME ada1 ada2

but in this can it require some kinda gptid.

Edit: Thanks for reply though.