Re: Xen 4.5 to 4.8 upgrade

[David Brownlee <abs%netbsd.org@localhost>]

On 17 December 2017 at 16:17, Dima Veselov <kab00m%lich.phys.spbu.ru@localhost> wrote:
> Greetings,
>
> I have an issue updating Xen 4.5 to 4.8 about using
> block devices in virtual machines.
>
> From the beginning I was using phy:/<block>,xvda,w notation,
> which is now deprecated. It still works on Xen 4.5 on NetBSD
> 7-STABLE with LVM on top. Also, I notice that VM start is
> fast, without any delay.
>
> After upgrading to Xen 4.8 built from pkgsrc (1, Dec, 2017) this
> do not work anymore, complaining:
>
> [root@midgard ~]$ xl create -c /etc/xen/rpd
> Parsing config from /etc/xen/rpd
> xenstore-read: not found
> libxl: error: libxl_exec.c:118:libxl_report_child_exitstatus: /usr/pkg/etc/xen/scripts/block /local/domain/0/backend/vbd/1/51712 [733] exited with error status 127
> libxl: error: libxl_create.c:1255:domcreate_launch_dm: unable to add disk devices
>
> Experiments says that I may not use block devices anymore.
> What I tried:
> disk = [ 'phy:/dev/mapper/midgard-rpd,xvda,w' ]
> disk = [ 'phy:/dev/midgard/rpd,xvda,w' ]
> disk = [ '/dev/mapper/midgard-rpd,,xvda,rw' ]
> disk = [ '/dev/mapper/midgard-rpd,raw,xvda,rw' ]
>
> I can use raw devices in any notation, but there is a delay on VM start,
> and after start they stuck on XENBUS: Waiting for devices to initialise:
> phase.
>
> What is wrong in Xen 4.8 on NetBSD-7-STABLE (possibly with LVM).
>
> Not tested on HVM VMs, only on PV.

I'm running unbuntu under NetBSD xen 4.8 (was 4.5, then 4.6 first :)

my cfg is below:

name = "test"
memory = "3700" # 1870 Matches Rackspace '2G' server
disk = [ 'phy:/dev/mapper/vg0-test,xvda,w' ]
vif = [ 'mac=02:00:00:00:01:01, bridge=bridge0', ]
bootloader = "pygrub"
vcpus = 2

It may help to make sure you are not mixing 4.5 and 4.8 etc config or
startup scripts (move all your old etc/xen files away and start with
the stock 4.8 files).

Thanks

David