> >>>> > >>>> > >>>> > >>>> Hi, > >>>> > >>>> I've observed some latency issues, for example, changing focus from one > >>>> terminal to another is a bit sluggish. Typing isn't too bad. > >>>> Interaction with the sliding GNOME unlock screen and drawing the desktop > >>>> after unlock is painfully slow. > >>>> > >>> > >>> Looks like your problems are due to a low bandwidth instead of high > >>> latency. Does spice detect a low bandwidth (should be written in the > >>> logs) > >>> ? > >>> > >> > >> Can you suggest which log file to check, or journalctl and a possible > >> grep command? > >> > > > > They are in /var/log/libvirt/qemu (at least on my machines). > > Should not be big to require a grep, unless you enable additional > > logs. > > > > Thanks, here is what I found: > > grep latency /var/log/libvirt/qemu/${VM}.log | cut -f3 -d: > latency 6.442000 ms, bitrate 15242858 bps (14.536722 Mbps) > latency 4.716000 ms, bitrate 18609384 bps (17.747292 Mbps) > latency 7.116000 ms, bitrate 15983891 bps (15.243426 Mbps) > latency 12.324000 ms, bitrate 15829951 bps (15.096618 Mbps) > latency 7.526000 ms, bitrate 19341556 bps (18.445545 Mbps) > latency 3.726000 ms, bitrate 16404604 bps (15.644650 Mbps) > latency 6.999000 ms, bitrate 20247558 bps (19.309576 Mbps) > latency 9.373000 ms, bitrate 22070154 bps (21.047739 Mbps) > latency 3.819000 ms, bitrate 19262965 bps (18.370595 Mbps) > latency 5.808000 ms, bitrate 16567434 bps (15.799936 Mbps) > latency 53.710000 ms, bitrate 4911212 bps (4.683697 Mbps) LOW BANDWIDTH > latency 100.954000 ms, bitrate 821117 bps (0.783078 Mbps) LOW BANDWIDTH > latency 41.180000 ms, bitrate 593653 bps (0.566152 Mbps) LOW BANDWIDTH > latency 6.116000 ms, bitrate 15928322 bps (15.190432 Mbps) > latency 7.282000 ms, bitrate 13945728 bps (13.299683 Mbps) > latency 8.717000 ms, bitrate 6145905 bps (5.861192 Mbps) LOW BANDWIDTH > latency 6.423000 ms, bitrate 14845097 bps (14.157388 Mbps) > latency 2.085000 ms, bitrate 5363208 bps (5.114754 Mbps) LOW BANDWIDTH > latency 5.981000 ms, bitrate 3645399 bps (3.476523 Mbps) LOW BANDWIDTH > latency 13.411000 ms, bitrate 17843917 bps (17.017285 Mbps) > latency 6.944000 ms, bitrate 11591709 bps (11.054715 Mbps) > latency 8.826000 ms, bitrate 16924500 bps (16.140461 Mbps) > latency 13.359000 ms, bitrate 18063947 bps (17.227122 Mbps) > latency 1.068000 ms, bitrate 20059355 bps (19.130092 Mbps) > latency 5.237000 ms, bitrate 6574913 bps (6.270326 Mbps) LOW BANDWIDTH > latency 1.022000 ms, bitrate 6562924 bps (6.258892 Mbps) LOW BANDWIDTH > latency 1.916000 ms, bitrate 19701969 bps (18.789262 Mbps) > latency 1.029000 ms, bitrate 17367559 bps (16.562995 Mbps) > Well... this confirm my theory of just a low bandwidth :-) Looks like your connection goes up and down. Are you using WiFi ? > >> > >>>> The virtual server I connect to runs Debian jessie and GNOME 3 desktop, > >>>> it is a default install: > >>>> Xorg = 2:1.16.4-1 > >>>> xserver-xorg-video-qxl = 0.1.1-2+b1 > >>>> spice-vdagent = 0.15.0-1.2 > >>>> > >>>> I'm monitoring the latency of the connection to the KVM/libvirt/SPICE > >>>> server with Smokeping, average ping time is about 0.8ms, no packet loss. > >>>> > >>> > >>> With such network latency you should not have much network latency > >>> issues, unless ssh (which seems you are using add a lot of it) add this > >>> issue. > >>> > >>>> > >>>> I've setup the KVM/libvirt/SPICE host like this: > >>>> Debian stretch > >>>> Kernel = 4.9.13 > >>>> libspice-server1 = 0.12.8-2.1 > >>>> libvirt0 = 3.0.0-3 > >>>> > >>>> > >>>> I've tried using both virt-manager and virt-viewer as clients on a > >>>> Debian jessie system, connecting over SSH to the KVM host, these are the > >>>> client versions: > >>>> > >>>> virt-manager = 1:1.0.1-5 > >>>> virt-viewer = 1.0-1 > >>>> > >>> > >>> Can you try without SSH? > >>> > >> > >> OK, I tried this: > >> > >> virsh edit <domain> and changed the listen IP to 0.0.0.0 > >> > >> Then I used spicy to connect directly to the port as I wasn't sure how > >> to tell virt-manager or virt-viewer to connect directly to the SPICE port. > >> > >> I found some things are a bit faster but it is still not ideal > >> > >> In particular, rendering the gray background of the GNOME unlock screen > >> appears very slow, it renders one line at a time from top to bottom, it > >> takes several seconds. Rendering the desktop background image (default > >> Debian theme) was also slow. I understand that I could change the > >> background image, but the gray lock screen, being a single colour, > >> shouldn't that render more quickly? > >> > > > > weird, looks like is not compressing at all! > > With remote-viewer you can add options like > > --spice-preferred-compression=glz > > (see "remote-viewer --help-spice" command), you should be able to connect > > with "remote-viewer spice://<ip>:<port>" (not using ssh). > > > > OK, using remote-viewer and not using SSH it now appears a lot faster > rendering the unlock screen and the desktop. > >From a quick research looks like even virt-viewer support same compression option of remote-viewer and also supports ssh (not clear if supported by remote-viewer too). > This runs over a WAN connection so most ports, including SPICE, are > firewalled by default, I only tested it briefly with that port open. Is > it considered safe to allow access to that port? > Absolutely not! Unless you configure SSL on top and disable not encrypted connections (not sure how). > I would normally consider running something like that over IPsec so that > only trusted hosts can connect, should that have less overhead than > running it over SSH or is there another way to go about it? > I would stick to default SSH or setup properly SSL but is just personal opinions. All 3 solutions (SSH, SSL or IPsec) had an encryption layer. > Regards, > > Daniel > I'm sure somebody more expert on client and server configurations will feel my gaps. Frediano _______________________________________________ Spice-devel mailing list Spice-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/spice-devel