freebsd stable - Apr 2021 - ZFS (in virtual machine): $HOME being a dataset causes xauth to timeout- access delays?

Hi there,

I have FreeBSD 12-STABLE in VirtualBox 5.2.44 on Windows 10. All the
"disks"
are file-backed virtual disks.

I noticed that after making $HOME a ZFS dataset, there were delays ...
- generally in start of Xorg;
- exhibited by xauth (after using "startx") error messages about
timeout
  with authority files.

After reverting back $HOME not being a dataset on its own as before, there
are
no delays in start of Xorg; nor are any timeout message from xauth as
before.

Has anybody else noticed that?


  - parv


Before making $HOME (/aux/home/parv) a dataset ...

  aux0 mounted at /aux
  aux0/home at /aux/home

Conversion of $HOME to a dataset ..

  % zfs create aux0/home/parv2
  % mv /aux/home/parv/* /aux/home/parv2/
  % mv /aux/home/parv/.* /aux/home/parv2/
  % rm -rf /aux/home/parv
  % zfs rename aux0/home/parv2 aux0/home/parv

On Thu, Apr 1, 2021 at 3:38 PM parv/freebsd wrote:

I am wondering if $SRC_BASE, $MAKEOBJDIRPREFIX, & $WRKDIRPREFIX being
ZFS datasets now would increase compile time. I will found that out in
few weeks (in case of buildworld & kernel) as earlier I had both $SRC_BASE
&
$MAKEOBJDIRPREFIX as plain directories & took ~5--6 hours.

I have FreeBSD 12-STABLE in VirtualBox 5.2.44 on Windows 10. All the
"disks"
> are file-backed virtual disks.
>
> I noticed that after making $HOME a ZFS dataset, there were delays ...
> - generally in start of Xorg;
> - exhibited by xauth (after using "startx") error messages about
timeout
>   with authority files.
>
> After reverting back $HOME not being a dataset on its own as before, there
> are
> no delays in start of Xorg; nor are any timeout message from xauth as
> before.
>
> Has anybody else noticed that?
>
...

  - parv