FreeBSD on Amazon AWS EC2 long standing performance problems

Sean Chittenden seanc at
Wed Feb 10 16:48:04 UTC 2021

Expect to see something about this on this year's Community Survey and the
Core Team will do something with this information.

Cloud has been an increasingly important workload for FreeBSD users.  Or at
least, our community is moving a fair number of workloads to virtualized
metal, and running on the cloud is in need of attention as or more than
some of our other subsystems.  Many of the people who have the skills to
jump in and diagnose and fix this type of problem have been sucked up with
other professional commitments and aren't available.  Which is to say, we
need to increase the depth of our bench for performance-related work.

But if someone's reading this thinking, "well I'll wait until Core...."
don't wait!  Jump in.

If people are looking for a single starting point, I'd suggest trying to
conjure up an iflib-backed ethernet driver and reducing the administrative
friction of spinning up one of our images in the Cloud.  "Secure by
default" or conservative image defaults aren't doing anyone any favors in
the cloud era.

Or begin porting the io_uring kernel interface and begin working down the
stack into the driver layer.

$0.02. -sc

On Wed, Feb 10, 2021 at 8:06 AM Gunther Schadow <raj at> wrote:

> I think we got enough feed back now from other professionals to suggest
> that it
> would do the FreeBSD project good to acknowledge the issue and create some
> sort
> of work in progress / project statement, perhaps a wiki, where people can
> flock
> to to look for workarounds, current statue, just to not feel so lost and
> lonely
> and wondering if anybody cares at all. Such a meeting-point could at least
> be
> something of a self-help group, for emotional support and positive
> thinking =8).
> I have a slight sign of hope also: in my latest Amazon Linux db server
> deployment
> the performance is only half of what I got in my previous db server
> deployment.
> Go figure. But it's a fresh launch and I can't figure out what else I had
> optimized
> with the previous Amazon Linux box. So, while not improving anything, it
> at least
> closes the inequality between Linux and FreeBSD in the socialistic way ;)
> Now I am trying the FreeBSD install again with the same disk setup.
> Because one
> thing I clearly know is that it makes a huge difference of having one
> large EBS
> device and a single partition / file system vs. the same large EBS device
> with
> many partitions and file systems, separating tables, indexes, temporary
> sort space,
> etc. so that there is less random access contention on a single file
> system.
> Why that is important, I wonder, actually. And it's not the underlying EBS
> that
> matters so much. Like in bare metal world, the approach would be separate
> disks
> vs. striping (RAID-0) to get more spindles involved instead of having disk
> seek.
> But none of that should mater that much any more with SSD drives (which
> EBS gp2 and
> gp3 are!)
> Fortunately now Amazon has gp3 volumes also which support 3000 io
> transactions
> per second (IOps) and 250 or up to 1000 MB/s throughput despite being as
> small as
> 4 GB. So what I'm doing now is instead of a partitioned 1 TB gp2 volume
> with many
> partitions, I make myself over 20 separate smaller gp3 volumes, the
> advantage of
> this is that I can individually resize those without colliding with the
> neighboring
> partition.
> Tomorrow I should have better comparison numbers for my database on both
> Linux and
> FreeBSD configured the exact same way, and it might be closer now. But
> sadly only
> in the socialist way.
> regards,
> -Gunther
> On 2/6/2021 9:55 AM, Mark Saad wrote:
> > On Feb 6, 2021, at 7:07 AM, Łukasz Wąsikowski <lukasz at>
> wrote:
> > All
> >    So what I was getting at, is do we have good data on what the issue
> is ? Can we make a new wiki page on the FreeBSD wiki to track what works
> what and  doesn’t .  Does one exist ?
> >
> > To be clear we should check if the issue something that aws is doing
> with their xen platform , kvm/qemu one or common to all ? Also does that
> same issue appear on google and Microsoft’s platforms?  This will at least
> get some bounds on the problem and  what if any fixes may exist .
> > There are some commercial FreeBSD products running on aws . Maybe the
> vendors know some stuff that can help ?
> >
> >
> > Thoughts ?
> >
> > ---
> > Mark Saad | nonesuch at
> >
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