Re: XEN 4.11 and 9.99.48 DOMU performance

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Tue, Mar 10, 2020 at 04:20:22PM +0100, Frank Kardel wrote:
> This is my first XEN setup so I may have misconfigured something:
> 
> I have a 4G DOM0 on a 512G System with a EPYC 7302P 16-Core Processor.
> 
> On that I configured a 400G DOMU with 12 vcpus. like this:
> 
> name = "system"
> kernel = "/netbsd-XEN3_DOMU.gz"
> memory = 400000
> cpus="all"
> vcpus=4
> maxvcpus=12
> vif = [ 'mac=aa:00:00:d1:00:01,bridge=bridge0',
>         'mac=aa:00:00:d1:00:02,bridge=bridge1' ]
> disk = [ 'file:/data0/xen-roots/root-Alpine-system.img,0x0,w',
>          'phy:/dev/wedges/data1,0x1,w' ]
> 
> On that I run postgresql 11 attempting to load a 1TB database.
> 
> Usually this workload keeps a machine continually busy cpu/io-wise.
> 
> I was expecting that I/O via the xen backend would be the bottleneck.
> 
> Instead DOM0 is only seldom busy for IO. DOMU is crawling along sleeping
> 
> at all sorts of places:


What does
iostat 5

show about the disks, in the dom0 and domU ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--