New drive won't appear to be used as spare

Hi All,
I’ve added my first spare drive, and it won’t appear as available. The drive initially appeared as I’d expected, with the error about “Drive Integrity Feature.” I ran an sg_format successfully, and from that point on, the drive appears in the list of disks. It’s listed as n/a in Pools. I tried re-running sg_format, which also succeeded, and here I am.

The drive is not listed as Available on the Storage tab. It does not appear as available to add as a spare in the Pool wizard.

How do I get it from whatever limbo it’s in, to becoming a ready-to-use spare?

System Info:
Hardware:

  • Dell T430 (Single Intel(R) Xeon(R) CPU E5-2630 v3 @ 2.40GHz)
  • 32gb SK HYNIX 16GB HMA82GR7MFR8N-UH DDR4-2400 ECC RDIMM 2Rx8 PC4-19200T-R CL17 Server Memory

SAS:

SanDisk SD8SBBU2 223gb Read Cache SSD
TOSHIBA MQ01ABD1 931gb Log Disk [2x] Mirrored

SAS Storage ZRaid3:

  • ST2000LM007 1R81 [6x]
  • ST2000NX0463
  • ST2000LM003 HN M [3x]
  • ST2000LM007 1R81

SATA:

  • SSD 128G Boot Pool [2x] Mirrored

  • iDrac Express Firmware=2.40.40.40

  • TrueNAS 25.04.2.3

Running Stuff:

  • VM: HomeAssistant
  • Applications: immich, Calibre