The Missing Disk could be part of a Mirror and the Diskgroup could have in its internal structure some information regarding the original structure, preventing the Missing Disk to be removed.
Please remove the volume first, then retry to remove the disk
dg testdg default default 17000 1692083701.3802.rhel86a
dm rhel86a_vmdk0_3 rhel86a_vmdk0_3 auto 65536 2027264 -
dm rhel86a_vmdk0_4 rhel86a_vmdk0_4 auto 65536 2027264 -
v vol01 - ENABLED ACTIVE 204800 SELECT - fsgen
pl vol01-01 vol01 ENABLED ACTIVE 204800 CONCAT - RW
sd rhel86a_vmdk0_3-01 vol01-01 rhel86a_vmdk0_3 0 204800 0 rhel86a_vmdk0_3 ENA
v vol02 - ENABLED ACTIVE 204800 SELECT - fsgen
pl vol02-01 vol02 ENABLED ACTIVE 204800 CONCAT - RW
sd rhel86a_vmdk0_4-01 vol02-01 rhel86a_vmdk0_4 0 204800 0 rhel86a_vmdk0_4 ENA
# vxassist -g testdg remove volume vol02
# vxdg -g testdg rmdisk rhel86a_vmdk0_4
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