understanding remote image viewing options

> On Sun, 10 Nov 2013, David T. Lewis wrote:
>
>> For information - no action required:
>>
>> Our squeaksource.com service is running with no apparent problems, but
>> there is a possibility of problems arising in the next day, so I am
>> sending this for information.
>>
>> I checked our squeaksource.com image on box3 via VNC about an hour ago,
>> and noticed an error notifier related to startup processing following
>> an image save. The error was related to port 8888 already in use. I
>> closed the notifier, then found that http://squeaksource.com was no
>> longer active.  I made a backup copy of the most recently saved disk
>> image (in a BACKUPS subdirectory), then saved the image and restarted
>> it.
>>
>> Squeaksource.com is running normally, but VNC access is no longer
>> working. This means that something failed in the startup processing,
>> and this may lead to problems later on. It also means that it is
>> hard to debug, because I no longer have VNC access.
>>
>> I cannot do anything further tonight, but will follow up tomorrow
>> to correct the problem.
>
>
> It would be worth installing xpra[1][2], and starting the image with it.
> IIRC the box has debian installed on it, so the following steps should work:
>
>
> On the server:
>
> Installation:
> $ sudo apt-get install xpra
>
> Start xpra on display #100:
> $ xpra start :100
>
> Start the VM (this might have to be different on the server):
> $ DISPLAY=:100 squeak -vm-sound-null squeaksource.image
>
>
> On your machine:
>
> Once you have xpra installed, you can attach to squeak running on the server
> via ssh:
>
> $ xpra attach --encoding=jpeg --auto-refresh-delay=0.1 ssh:box3:100
>
> Here box3 is the label defined in the ssh config file, which can usually be
> found in $HOME/.ssh/config
> If you don't have such entry or file yet, then the following will do the
> trick:
>
> Host box3
>      hostname box3.squeak.org
>      user <your_username>
>      compression yes
>      port 22
>
> You might want to use a different value for the --auto-refresh-delay
> parameter.
>
> To detach from the image - but keep it running on the server - simply stop
> the xpra on your machine with Ctrl-C.
>
>
> Levente
>
> [1] http://xpra.org/
> [2] https://help.ubuntu.com/community/Xpra
>
>>
>> Dave
>>
>>
>

>
> (VNC desktop) Sharing entire desktops on my LAN is handy for accessing
> multiple running images on another machine all at once.  The downside
> is that it's single-user, since anyone else trying to use the desktop
> will be disrupted.
>
> (VNC display :1) Sharing an alternate display by starting xtightvnc on
> the server, starting Squeak vm with the -display :1 argument, one can
> then use remote viewing tools like Remmina to reconnect to that
> running Squeak image.
>
> (xpra) This is for sharing a single program at a time.  You can start

> On Mon, 11 Nov 2013, Chris Muller wrote:
>
>> Levente, I'm glad you posted about xpra, because I've been meaning to
>> try it out as well as Squeak's RFB.
>>
>> I would like to ask you (and others here of course!) about options for
>> remote image operation, and try to understand the differences between
>> them.  By my understanding, we have 1) VNC, 2) Squeak RFB and 3) xpra.
>
> We use Squeak's RFB and xpra at the same time. xpra is less
> responsive, so we use it only if RFB doesn't work for some reason
> (e.g.: pressing Alt+. is likely to interrupt the RFB process, which
> can be fixed using xpra).
>
>>
>> (VNC desktop) Sharing entire desktops on my LAN is handy for accessing
>> multiple running images on another machine all at once.  The downside
>> is that it's single-user, since anyone else trying to use the desktop
>> will be disrupted.
>>
>> (VNC display :1) Sharing an alternate display by starting xtightvnc on
>> the server, starting Squeak vm with the -display :1 argument, one can
>> then use remote viewing tools like Remmina to reconnect to that
>> running Squeak image.
>>
>> (xpra) This is for sharing a single program at a time.  You can start
>
> You can run multiple programs on the server using the same display.
>
>> an image on a particular display.  This seems similar to above except
>> it can run across ssh rather than having to share a VNC password..?
>> One thing I was wondering was whether the Squeak vm could be started
>> with the -display arg like above or only that strange way you said:
>> $DISPLAY=:100 squeak -vm-sound-null squeaksource.image..?
>
> The main advantages over VNC are:
> - all windows will appear on your desktop, not in a separate window
> - supports shared sessions (only the newer versions)
> - lightweight
>
>>
>> (Squeak RFB) From Ian, my understanding is this uses the image itself
>> to send its graphics over the network for remote op.  Might slow down
>> the image but the advantage here could be if you're on a machine on
>> which you cannot install and/or run remote viewing software..?
>
> Squeak's RFB is the most responsive among these three options, because
> it knows exactly what has changed on the screen. If the remote server
> is not too far away from you, then this will feel like you're working
> with an image on your machine. It requires way less resources than
> you'd expect.
>
> We use the following hack to make Squeak display the mouse pointer:
> ActiveHand userInitials: ' ' andPicture: nil.
>
>
> Levente
>