Re: openzfs panic: VERIFY3U(offset, <, dn->dn_datablksz) failed

On 24 Apr 2026, at 14:18, Alexander Leidinger wrote:
> Hi,
>
> recent current (last commit 2026-04-23-222413).
>
> short:
> #3  0xffffffff805502f7 in vpanic (
>     fmt=0xffffffff82556d5d "VERIFY3U(offset, <, dn->dn_datablksz) 
> failed (%llu < %llu)\n", ap=ap@entry=0xfffffe0228f57c70)
>     at /space/system/usr_src/sys/kern/kern_shutdown.c:974
>         buf = "VERIFY3U(offset, <, dn->dn_datablksz) failed 
> (9223372036854775807 < 24576)\n", '\000' <repeats 180 times>
>         __pc = 0x0
>         __pc = 0x0
>         __pc = 0x0
>         other_cpus = {__bits = {16777213, 0 <repeats 15 times>}}
>         td = 0xfffff80741b6e780
>         bootopt = <unavailable>
>         newpanic = <optimized out>
>
> See attachment for a full backtrace. vmcore available.
>
> I can trigger this with a postgresql18 initdb call (I tried an upgrade 
> from postgresql 17 to 18, copy & paste of the UPDATING entry for the 
> initdb call).
>
> No zpool status issues, I started a scrub to see if it detects some 
> issues. This is a 5T pool on spinning drives, so it may take a moment.
>
I’m seeing the same panic (somewhat regularly, without obvious 
trigger), so I’m fairly confident it’s not some obscure corruption 
in your pool.

Best regards,
Kristof