svn commit: r356758 - in head/usr.sbin/bsdinstall: . scripts

[Slawa Olhovchenkov]

On Thu, Jan 16, 2020 at 04:19:52PM -0800, Devin Teske wrote:

> 
> 
> > On Jan 16, 2020, at 16:03, Slawa Olhovchenkov <slw at zxy.spb.ru> wrote:
> > 
> > On Thu, Jan 16, 2020 at 02:43:37PM +0700, Eugene Grosbein wrote:
> > 
> >> 16.01.2020 4:41, Ed Maste wrote:
> >> 
> >>> On Wed, 15 Jan 2020 at 16:10, Eugene Grosbein <eugen at grosbein.net> wrote:
> >>>> 
> >>>> There are multiple scenarios there ZFS may be sub-optimal at least: small i386 virtual guests
> >>>> or 32-bit only hardware like AMD Geode, or big amd64 SSD-only systems with bhyve and multiple guests
> >>>> that need lots of memory and should not fight with ZFS for RAM etc.
> >>> 
> >>> That may well be the case, but our defaults should represent the
> >>> configuration that's desirable to the largest set of users, and IMO
> >>> that's ZFS in most cases today.
> >>> 
> >>> It might be that we should default to UFS on i386 and ZFS on amd64?
> >> 
> >> UFS may be better for any virtual guest having RAM less or equal to 4GB.
> > 
> > Why?
> 
> ZFS does not do any auto-tuning in that situation and you’ll quickly
> find you’ll have a dozen or more tunables in loader.conf tailored to
> your workload. Even moderate workloads require tuning in i386 and/or
> <=4GB environments with ZFS.

This (auto-tuning) can be fixed, I am do this.

> It is also highly inadvisable to mix UFS and ZFS — memory pressure from ARC can cause UFS cache evictions and vice-versa.

May be, don't test