Re: Odd X11 over SSH issue
Paul Kraus p...@kraus-haus.org writes: On Fri, Nov 23, 2012 at 4:31 PM, Lowell Gilbert freebsd-questions-lo...@be-well.ilk.org wrote: Yup, I just have not had a chance to chase that one down, and given that it happens once per SSH session, has not been a high priority. I mentioned it in the spirit of full disclosure. I would chock it up to network slowness, but I do not see the same behavior with Firefox, xload, or xclock. That's not a fair comparison, because tunneling a whole X server involves passing a lot more events than tunneling an application to run on your local server. This is particularly painful because the X protocols are highly serial. The VIrtualBox GUI (not the underlying VM console) should be comparable to Firefox in terms of network load. Yes, xclock and xload are much lower overhead as they are simpler apps. The difference between Firefox (measured at under 10 seconds to open the window) and VirtualBox (measured at 157 seconds to open the window) indicates that _something_ is wrong. Sorry if I was unclear. Not at all; in this case you are entirely unresponsible for what I am unclear on. I was, in fact, thinking of the console. The console is, in fact, what I was thinking of. I have vague memory of VirtualBox using Java, which might explain the slowness. That's more in your area of expertise than mine. I can't back that up, though, so I may be way off. I am running 3 different VMs on this server (soon to be more :-). One is WIn 2008 server as an RDP host for a specific application, the others ar FreeBSD VMs, one for DNS and DHCP, and the other for email / webmail. I manage the underlying Win 2008 instance via RDP (and that is how the end users connect), the two FreeBSD VMs do not run a window manager at all and they are managed via SSH connections. I use the VBoxHeadless executable to run the VMs for production use. Normally I make config changes with the command line tool VBoxManage, but in this case I had a FreeBSD VM that was not booting so I needed the console (and to make various changes to the config). It is running the VBox management GUI on the physical layer server that I am having fits with. If it is a network/protocol issue, ssh makes it harder to troubleshoot. Verbose output from the initiating side might tell you what is happening, although you would probably need to do some log analysis to separate out the different channels. I went back and checked the truss output, and the EAGAIN errors aren't interesting; they just mean there was no input on a non-blocking read from the socket. You also might want to check with the VirtualBox support channels, the freebsd-emulation list, and other obvious suspects. Also, building with a different frontend might make the X connection more lightweight. Is there any particular reason you don't let the X server run remotely and attach to it with something more latency-friendly, like vnc? I would expect that to work vastly better on any OS, just because you get X (specifically, its tendency to head-of-line blocking) out of its own way. The short answer to why X11 via SSH and not VNC for the management is that I have not found a very clean way to have the VNC service running for root without manual intervention to start it. Yes, I know I could script it, but that adds one additional layer that needs to be supported. That makes sense. You shouldn't have to run an X server on the base level system at all. P.S. I did get my VM repaired, very slowly and painfully, but I still need to track down the VBox GUI issue. Being able to clone, import, and export VMs is one of the reasons I use them at all... Be well. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Odd X11 over SSH issue
On Fri, Nov 23, 2012 at 6:43 PM, Paul Kraus p...@kraus-haus.org wrote: I am seeing very poor response time running the VitrualBox GUI via X11 tunneled over SSH via the Internet. The issue _appears_ to be limited to the VBox GUI as Firefox is reasonable. I am well aware of the latency issues tunneling X11 over SSH across the Internet, but that is what we are stuck with for the moment. The server is running FreeBSD 9 and is patched as of about 4 weeks ago. I see the same thing. But doing the same thing with CentOS(that is, CentOSis the host that VirtualBox runs on) goes pretty fast. My guess is that it is related to QT. -- chs, ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Odd X11 over SSH issue
On Fri, Nov 23, 2012 at 11:43 AM, Paul Kraus p...@kraus-haus.org wrote: I am seeing very poor response time running the VitrualBox GUI via X11 tunneled over SSH via the Internet. The issue _appears_ to be limited to the VBox GUI as Firefox is reasonable. I am well aware of the latency issues tunneling X11 over SSH across the Internet, but that is what we are stuck with for the moment. The server is running FreeBSD 9 and is patched as of about 4 weeks ago. Start it with --graphicssystem native -- Adam Vande More ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Odd X11 over SSH issue
On Fri, Nov 23, 2012 at 1:01 PM, Adam Vande More amvandem...@gmail.com wrote:
On Fri, Nov 23, 2012 at 11:43 AM, Paul Kraus p...@kraus-haus.org wrote:
I am seeing very poor response time running the VitrualBox GUI via X11
tunneled over SSH via the Internet. The issue _appears_ to be limited
to the VBox GUI as Firefox is reasonable. I am well aware of the
latency issues tunneling X11 over SSH across the Internet, but that is
what we are stuck with for the moment. The server is running FreeBSD 9
and is patched as of about 4 weeks ago.
Start it with --graphicssystem native
Tried it, did not make any noticeable difference, still over a
minute to open the window, but thanks for the suggestion. VBox is
version 4.1.22_OSE.
--
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Paul Kraus
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- Deputy Technical Director, LoneStarCon 3 (http://lonestarcon3.org/)
- Sound Coordinator, Schenectady Light Opera Company (
http://www.sloctheater.org/ )
- Technical Advisor, Troy Civic Theatre Company
- Technical Advisor, RPI Players
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Re: Odd X11 over SSH issue
Paul Kraus p...@kraus-haus.org writes: I am seeing very poor response time running the VitrualBox GUI via X11 tunneled over SSH via the Internet. The issue _appears_ to be limited to the VBox GUI as Firefox is reasonable. I am well aware of the latency issues tunneling X11 over SSH across the Internet, but that is what we are stuck with for the moment. The server is running FreeBSD 9 and is patched as of about 4 weeks ago. Observations: 1. When I first SSH into the box I see a long delay after the SSH tunnel is setup before being prompted for a password, and I do not know if this delay is related to the VBox issue. Details below. Running the ssh server with more debugging will probably tell you what's happening in this area. 2. When I fire up VirtualBox it takes _minutes_ before the window opens and each action (drawing contents, mouse clicks) takes additional _minutes_. Looking at the VirtualBox process with truss I see many, many errors of the form: read(7,0x80193a02c,4096) ERR#35 'Resource temporarily unavailable' where fd 7 is a socket. This could be a red herring. Or not. But you can't tell without tracing down exactly what the socket is, and what is expected to be read from it. Probably not the first path worth exploring, although you may need to go there eventually. I would chock it up to network slowness, but I do not see the same behavior with Firefox, xload, or xclock. That's not a fair comparison, because tunneling a whole X server involves passing a lot more events than tunneling an application to run on your local server. This is particularly painful because the X protocols are highly serial. Is there any particular reason you don't let the X server run remotely and attach to it with something more latency-friendly, like vnc? I would expect that to work vastly better on any OS, just because you get X (specifically, its tendency to head-of-line blocking) out of its own way. Be well. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Odd X11 over SSH issue
On Fri, Nov 23, 2012 at 4:31 PM, Lowell Gilbert
freebsd-questions-lo...@be-well.ilk.org wrote:
Observations:
1. When I first SSH into the box I see a long delay after the SSH
tunnel is setup before being prompted for a password, and I do not
know if this delay is related to the VBox issue. Details below.
Running the ssh server with more debugging will probably tell you what's
happening in this area.
Yup, I just have not had a chance to chase that one down, and
given that it happens once per SSH session, has not been a high
priority. I mentioned it in the spirit of full disclosure.
I would chock it up to network slowness, but I
do not see the same behavior with Firefox, xload, or xclock.
That's not a fair comparison, because tunneling a whole X server
involves passing a lot more events than tunneling an application to run
on your local server. This is particularly painful because the X
protocols are highly serial.
The VIrtualBox GUI (not the underlying VM console) should be
comparable to Firefox in terms of network load. Yes, xclock and xload
are much lower overhead as they are simpler apps. The difference
between Firefox (measured at under 10 seconds to open the window) and
VirtualBox (measured at 157 seconds to open the window) indicates that
_something_ is wrong.
Sorry if I was unclear. I am running 3 different VMs on this
server (soon to be more :-). One is WIn 2008 server as an RDP host for
a specific application, the others ar FreeBSD VMs, one for DNS and
DHCP, and the other for email / webmail. I manage the underlying Win
2008 instance via RDP (and that is how the end users connect), the two
FreeBSD VMs do not run a window manager at all and they are managed
via SSH connections. I use the VBoxHeadless executable to run the VMs
for production use. Normally I make config changes with the command
line tool VBoxManage, but in this case I had a FreeBSD VM that was not
booting so I needed the console (and to make various changes to the
config).
It is running the VBox management GUI on the physical layer server
that I am having fits with.
Is there any particular reason you don't let the X server run remotely
and attach to it with something more latency-friendly, like vnc? I would
expect that to work vastly better on any OS, just because you get X
(specifically, its tendency to head-of-line blocking) out of its own way.
The short answer to why X11 via SSH and not VNC for the management
is that I have not found a very clean way to have the VNC service
running for root without manual intervention to start it. Yes, I know
I could script it, but that adds one additional layer that needs to be
supported.
P.S. I did get my VM repaired, very slowly and painfully, but I still
need to track down the VBox GUI issue.
--
{1-2-3-4-5-6-7-}
Paul Kraus
- Principal Consultant, Business Information Technology Systems
- Deputy Technical Director, LoneStarCon 3 (http://lonestarcon3.org/)
- Sound Coordinator, Schenectady Light Opera Company (
http://www.sloctheater.org/ )
- Technical Advisor, Troy Civic Theatre Company
- Technical Advisor, RPI Players
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