Subject: Re: Xen2 vs Xen3: features and stability?
To: Johan Ihren <johani@johani.org>
From: Luke Crawford <lsc@prgmr.com>
List: port-xen
Date: 11/22/2006 10:31:44
Hmm. I've mostly moved off of my NetBSD 3 (xen2) Dom0s because while
once up, they are rock-solid, the xend daemon doesn't seem so stable;
after adding 10 or 12 DomUs, the system does not allow me to startup or
shutdown any more guests. Also, support for linux 2.6 DomU kernels is a
requirement in my environment.
That said, the difference in uptime between my Linux Xen3 Dom0s and my
rock-solid NetBSD Xen2 Dom0 is rather shocking.
linux/Xen3:
lsc@auburn:~$ uptime
10:12:38 up 20 days, 11:02, 7 users, load average: 0.00, 0.02, 0.00
NetBSD/Xen2:
137: {1} uptime
10:00AM up 121 days, 19:41, 5 users, load averages: 5.56, 4.34, 4.09
137: {2} uname -a
NetBSD 137 3.0.1 NetBSD 3.0.1 (amy-XEN0) #1: Wed Jul 12 02:33:02 PDT 2006
lsc@:/usr/obj/sys/arch/i386/compile/amy-XEN0 i386
(The NetBSD box is the only one that meets any kind of reasonable SLA)
so yes, I am strongly considering moving to NetBSD4; the big problem with
Xen3 is that it seems to still be something of a moving target (changes
were made between 3.0.2-2 and 3.0.3 that broke NetBSD and FreeBSD DomU
support... NetBSD support is fixed now in -current and 4.0)
Of course, the other option is to put the effort into figuring out what's
wrong with xen2- at least then the specification isn't going to move out
from under you; there is significant demand for stable NetBSD/FreeBSD
virtual servers.
On Wed, 22 Nov 2006, Johan Ihren wrote:
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> Hi,
>
> I've been running xen2 with great success for quite some time but I realize
> its days are numbered. So when evaluating making the leap for xen3 I notice
>
> a) that I haven't found a comparision between the two anywhere. There are
> bits here and there, like SMP domU's requiring xen3 and PCI access AFAIK
> requiring xen2, but no comprehensive summary. If there is such a document
> anywhere I'd much appreciate a pointer (and yes, I realize that a
> Linux-centric document is likely to point at features not yet available for
> NetBSD, and that's fine too, I can sort through that).
>
> b) what's the general feeling as to production worthiness of the xen3 stuff?
> As stable as xen2 (which is working just great for me, and I use it for a
> number of dom0's and dozens of domU's of different shapes and forms)?
>
> In general, as I don't need SMP at all, my gut feeling is that there's no
> real rush to change...
>
> Regards,
>
> Johan
>
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