Hi all, I have to choose between intel and amd server to host about 10 guests with a mid-high load. Which one do you suggest? intel or amd? I heard that amd is not limited by front side bus as intel cpus. Thanks Marco _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
I have look a bit in to it, (for my home computer) What i found was the there are two definite between Intel and AMD when it comes to virtualization (sorry I lost the URL for the info) What I found out was that AMD-V was all hardware but Intel-VT still has 2 things that was software emulate You can get some info from http://en.wikipedia.org/wiki/X86_virtualization -- Venlig Hilsen / Kind Regards /harly - live your dreams, don''t dream your life On Fri, Feb 29, 2008, Marco Strullato <marco.strullato@gmail.com> said:> Hi all, > I have to choose between intel and amd server to host about 10 guests > with a mid-high load. > > Which one do you suggest? intel or amd? I heard that amd is not > limited by front side bus as intel cpus. > > > Thanks > > Marco > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
If you''re planning on any HVM DomUs, then you should go for AMD. The real-mode issues are apparently fixed in Xen 3.2, but I haven''t yet seen any Intel success stories for 3.2 for the affected OSes (Solaris 10 and openSUSE 10, at least). You''ll also need to roll-your-own Xen for 3.2. Evan _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Evan Lavelle wrote:> If you''re planning on any HVM DomUs, then you should go for AMD. The > real-mode issues are apparently fixed in Xen 3.2, but I haven''t yet seen > any Intel success stories for 3.2 for the affected OSes (Solaris 10 and > openSUSE 10, at least). You''ll also need to roll-your-own Xen for 3.2. >Hello, I have an Intel Core 2 Quad (Q6600) system with vmx support enabled. I''ve downloaded, compiled, and installed Xen 3.2.0 (and made sure to compile hvmloader and get it installed). dom0 system is running Debian Etch 4.0r3, and the Xen 2.6.18.8 kernel. Yesterday I was trying to create a Xen HVM for the purposes of installing a Debian Etch system (I''ve got several Debian Etch PVMs which work fine, but I wanted to set up an HVM for some other experimenting). After reading through several mailing list posts, web sites, FAQs, etc. I was unable to actually perform an install. As soon as I try to create the HVM, and connect to it via VNC, I always tend to get a black/blank screen, and can never get it to change. After some playing (I believe with the attempts to get information available on the "serial port" so I could access it through xm console (is this a correct assumption?)), I''ve never been able to see it display anything, but sometimes I get what appears to be SOMETHING to spit out-- the cursor moves over several spaces, but no viewable characters are actually printed. I wonder if I''ve got a kernel option set the wrong way for this particular feature? This morning I see the post regarding intel or amd, so at the very least I''d like to seek some clarification on whether or not my particular failures in getting a working Xen HVM up and running are due to these real-mode issues (or if it is just some obvious detail I am missing). Again, all I''m after is to be able to install Debian off the pointed to netinst ISO image, and get a system up and running. My previous experience with Xen HVMs was in relation to setting up a WindowsXP HVM back on Xen 3.0.3 (of which I referenced that config file in coming up with my new one on this Xen 3.2 setup). Attached are my Xen dom0 kernel .config and Xen HVM config file. If anyone could point me in the right direction that would be fabulous. Thanks. -Matthew -- Matthew Haas Visiting Instructor Corning Community College Computer & Information Science http://lab46.corning-cc.edu/haas/home/ "Writing should be like breathing; It is one of those important things we do." -- me _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Fri, 29 Feb 2008, Evan Lavelle wrote:> If you''re planning on any HVM DomUs, then you should go for AMD. The > real-mode issues are apparently fixed in Xen 3.2, but I haven''t yet seen any > Intel success stories for 3.2 for the affected OSes (Solaris 10 and openSUSE > 10, at least)What''s about these "real-mode issues", could anyone provide more information about this (any mainling list messages, Bug-reports)? If openSUSE is affected, every Linux-based OS will (at least with same kernel) - or not? Thanks & best regards, Mark Weinem -- Mark Weinem Jabber: weinem@jabber.cz _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Fri, 29 Feb 2008, Michael Harly wrote:> What I found out was that AMD-V was all hardware but Intel-VT still has 2 > things that was software emulateCould someone provide more infos about this? Best regards, Mark -- Mark Weinem Jabber: weinem@jabber.cz _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Mark Weinem wrote:> What''s about these "real-mode issues", could anyone provide more > information about this (any mainling list messages, Bug-reports)? > > If openSUSE is affected, every Linux-based OS will (at least with same > kernel) - or not?I''ve spent a lot of time Googling, but I''ve never found a list. All I know for sure is: 1 - don''t work: Solaris 10 (Sun has 3.1 patches, which I think are all in 3.2) openSUSE 10.3 2 - do work (I''ve tried): SLES 9.4 SLES 10.1 Centos 5 Fedora 8 RedHat 7.2 Windows 2000 Windows XP Evan _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Evan Lavelle
2008-Feb-29 16:43 UTC
Re: Xen 3.2 HVM help (was Re: [Xen-users] intel or amd?)
Random thoughts:
1 - console doesn''t work on HVM anyway; don''t use the -c
option
2 - use sdl for the install, not vnc (fewer variables)
3 - use a minimal config; something like (with changes for your name,
MAC address, file system, and qemu-dm location):
kernel = "/usr/lib/xen/boot/hvmloader"
builder =''hvm''
memory = 512
name = "myhvm"
vcpus = 1
vif = [ ''type=ioemu, mac=xx:xx:xx:xx:xx:xx,
bridge=xenbr0'' ]
disk = [ ''phy:/dev/VG_Guests/FC8-64-001,ioemu:hda,w'' ,
''file:/dumps/ISO/FC8-64/FC8-64.ISO,hdc:cdrom,r'']
device_model = ''/usr/lib64/xen/bin/qemu-dm''
boot = "cd"
sdl = 1
vnc = 0
vncviewer = 0
This works for all my hvms, but I add
usb = 1
usbdevice = ''tablet''
if it helps for the mouse tracking.
4 - if the install hangs early on, then you may have a real mode
problem. If so, try a text mode install if possible. If that doesn''t
work, give up. But, I thought this wasn''t a problem on 3.2 anyway; the
real-mode stuff was apparently rewritten in 3.2.
Evan
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Marco Strullato wrote:> Hi all, > I have to choose between intel and amd server to host about 10 guests > with a mid-high load. > > Which one do you suggest? intel or amd? I heard that amd is not > limited by front side bus as intel cpus. > > > Thanks > > Marco > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >Well, Intel has working quad-core CPU''s. AMD tends to be better performance at lower CPU speeds, and lower power consumption, and thus better cooling. Many big vendors sell either at similar prices, but having one CPU core to dedicate to each guest domain can be handy. I personally prefer AMD due to better support for their newest features in the Linux world, so it''s a trade-off. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
jim burns
2008-Mar-02 04:31 UTC
x86 Virtualization requirements (was Re: [Xen-users] intel or amd?)
On Friday 29 February 2008 09:14:01 am Michael Harley wrote:> You can get some info from > http://en.wikipedia.org/wiki/X86_virtualizationThis link leads near the top to a link discussing requirements for an architecture to be virtualizable, about how efficient virtualization requires all sensitive instructions to be a subset of all privileged instructions (and therefore trapable) and from the x86 section - http://en.wikipedia.org/wiki/Popek_and_Goldberg_virtualization_requirements#IA-32_.28x86.29 they say: "IA-32 (x86) (Main article:X86 virtualization) The IA-32 instruction set contains 17 sensitive, unprivileged instructions[3]. They can be categorized in two groups: * Sensitive register instructions: read or change sensitive registers and/or memory locations such as a clock register or interrupt registers: o SGDT, SIDT, SLDT o SMSW o PUSHF, POPF * Protection system instructions: reference the storage protection system, memory or address relocation system: o LAR, LSL, VERR, VERW o POP o PUSH o CALL, JMP, INT n, RET o STR o MOV" MOV ??? That will really slow things down. How does xen handle this in an hvm domain? Does it trap all MOV instructions (even in a REP block), or does it just trap on illegal addresses? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Matthew Haas
2008-Mar-02 14:59 UTC
Re: Xen 3.2 HVM help (was Re: [Xen-users] intel or amd?)
Evan Lavelle wrote:> Random thoughts: > > 1 - console doesn''t work on HVM anyway; don''t use the -c option >In the past, I know better than to have attempted this.. but in recent explorations, I seem to have read somewhere that there''s a kernel option to output to serial port, and that the xm console for an HVM would in fact be the serial port output? Or did I misinterpret this?> 2 - use sdl for the install, not vnc (fewer variables) >I would if I were on the machine in question. As it is, it is at a remote location and I''m accessing it over a VPN... so unless I''m missing something (ie can I even use the SDL way if I''m NOT on the local machine''s console??) I can''t go this route.> vif = [ ''type=ioemu, mac=xx:xx:xx:xx:xx:xx, bridge=xenbr0'' ] >Is it essential to add the "bridge=xenbr0" ? Will networking not work in an HVM without it? And.. with all the recent talk about bridging and Xen 3.2, I get the impression xenbr0 isn''t used in the same capacity anymore... in which case, should I say "bridge=eth0" ? Or, is that referring to something else entirely?> 4 - if the install hangs early on, then you may have a real mode > problem. If so, try a text mode install if possible. If that doesn''t > work, give up. But, I thought this wasn''t a problem on 3.2 anyway; the > real-mode stuff was apparently rewritten in 3.2. >Out of the 30+ times I attempted to boot my HVM, maybe about 4-5 times did I actually/eventually see anything.. maybe a HVM POST screen (ie VGA BIOS, disk controller being "detected" etc.) or the initial debian text mode installer screen. I''m assuming when you say "text mode install" you mean non-X... which is all I''m shooting for (I''m not doing HVM in this case for X, I''m doing it for a fully contained machine that I can run some non-Xen kernels on). Thank you for your thoughts. I will keep plugging away with them in mind. -Matthew -- Matthew Haas Visiting Instructor Corning Community College Computer & Information Science http://lab46.corning-cc.edu/haas/home/ "Writing should be like breathing; It is one of those important things we do." -- me _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Sunday 02 March 2008 09:59:34 am Matthew Haas wrote:> I would if I were on the machine in question. As it is, it is at a > remote location and I''m accessing it over a VPN... so unless I''m missing > something (ie can I even use the SDL way if I''m NOT on the local > machine''s console??) I can''t go this route.If you are doing ssh with X forwarding (ssh -X hostname) over the VPN, either vnc or sdl will work fine.> > vif = [ ''type=ioemu, mac=xx:xx:xx:xx:xx:xx, bridge=xenbr0'' ] > > Is it essential to add the "bridge=xenbr0" ? > > Will networking not work in an HVM without it? > > And.. with all the recent talk about bridging and Xen 3.2, I get the > impression xenbr0 isn''t used in the same capacity anymore... in which > case, should I say "bridge=eth0" ? Or, is that referring to something > else entirely?Do a ''brctl show'' on the dom0. Whatever bridge peth0 is attached to would be the one you use in the bridge= parm, or just let it default. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
James Harper
2008-Mar-03 05:40 UTC
RE: Xen 3.2 HVM help (was Re: [Xen-users] intel or amd?)
> Evan Lavelle wrote: > > Random thoughts: > > > > 1 - console doesn''t work on HVM anyway; don''t use the -c option > > > > In the past, I know better than to have attempted this.. but inrecent> explorations, I seem to have read somewhere that there''s a kerneloption> to output to serial port, and that the xm console for an HVM would in > fact be the serial port output? > > Or did I misinterpret this?Nope, you are correct. I put an entry in my inetd.conf to invoke ''xm console <domainname>'' and then use a virtual serial port on my XP laptop to connect to Dom0, and can then use the windows debugger. James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users