OpenZFS: kldload zfs.ko freezes on i386 4GB memory

[Slawa Olhovchenkov]

On Thu, Oct 29, 2020 at 08:13:00PM -0700, Cy Schubert wrote:

> In message <E1kWvLj-0000GY-Ic.qroxana-mail-ru at smtp29.i.mail.ru>, qroxana 
> writes
> :
> > 
> > Hi,
> >
> > I have an old i386 machine running r364479. After upgrading to
> > r367045, running kldload zfs.ko freezes the whole system.
> >
> > I also tried to replace the 4GB memory with another 2GB one
> > and kldload zfs.ko works without freezing the machine.
> 
> ZFS ARC stresses memory. I've found a number of bad RAM chips over the 
> years using ZFS.
> 
> The OpenZFS upgrade significantly changed how it manages ARC. It's likely 
> that prior to the OpenZFS upgrade your memory wasn't stressed to the point 
> of failure. You can try to mask the problem by reducing your RAM clock rate 
> or or increase one of the other latency settings in your BIOS. However, 
> again, this only masks an already weak RAM chip.

Sounds like performance drop and regression