Hi, On Sun, Jul 19, 2015 at 01:01:40AM -0700, Dominique Laurain wrote: > Hello Viviane & Thierry, > > Very interesting feedbacks, thanks for sharing :-) > > Yes simple to go with USB keys, because now we can buy one 4Go at low > price. I am only worried about 1) how to boot on it for old computers > (and new ones too because for example my tablet don't have..only USB > port for electricity power) 2) data transfer speed from key to computer
For a tablet without USB port, well i guess there is nothing to do, or perhaps if it is able to boot from a SD card. For old computers that have a USB port but for which the BIOS is not able to boot on it, there is an small CD iso image with plopkexec on it in the live/ directory of the key. You can burn it from the live USB by inserting an empty writeable cdrom and clicking on the "Create a bootloader CD-ROM" icon. Then you can boot from the CD, ant it will be able to boot on the USB key. I did not test the "Create a bootloader CD-ROM" option for a while since it uses a new CDROM each time, so if you try it, please tell if it still works. This feature was suggested at http://article.gmane.org/gmane.comp.mathematics.sage.devel/62520 https://groups.google.com/d/msg/sage-devel/X1tZa6qyaQE/1N9qDY7UdvIJ Concerning the data transfer, with a decent USB drive, you can clone the key (3.1GB pf compressed data for version 6.7) in about 10 minutes (USB 2). Concerning the data transfer when the key is working, if you do not select "home persistence" option at boot, then everything is written in RAM, so there is no write access to the USB key. If you boot with the "home persistence" option, only the personal data (the one on /home/user/ directory) is actually written, so this is usually only about some small worksheets, or huge files downloaded from the internet which will be the bottleneck anyway. If you want to write something outside the home directory (e.g. install a Debian package), you should have a look at the "keep" module which can make custom snapshots. If you need huge fast data transfers, you should look for USB 3, note that external hard disk will work as well, or perhaps consider installing GNU/Linux on your machine. About reading the data from the key (e.g. when launching a new software), there is a possibility to copy its whole content to RAM at startup, but i did not enable this feature since the menu is quite big already and it wastes 3.1 GB of RAM. It is doable however. > For "switch" I do not mean a big one..I mean only one about 15cm x 10cm > x 5cm, you can easily store in bag. > > I defnitiely have to put in my to-do-list,practicing how to make a > booting SAGE USB key and collecting instructions for that.. Thierry, do > you have blog or github or internet web site where you have written USB > tips ? Yes, you can have a look at: http://sagedebianlive.metelu.net/ There are 4 levels of documentation: - Use the USB key you got from a friend : how to duplicate a key that works already - Download and install a USB key from an iso file : how to make a first key from the iso image found on the mirrors - Build and customize your own key : how to compile your own custom key with the software you want - Development : how to share your custom modules if they are of general interest I do not have much feedback on whether those texts are precise enough, so please do not hesitate to comment if there is something unclear. Ciao, Thierry > > Dominique > > > On Friday, 17 Jul 2015 20:00:49 UTC+2, Viviane Pons wrote: > > > > Dear all, > > > > this last week, I was giving a class in a summer school in Uganda, along > > with Jennifer Balakrishnan, on experimental mathematics (mine was > > combinatorics and Jennifer's was number theory). Both classes were based on > > Sage. Let me give you a feedback on using Sage here. > > > > Conditions; > > > > - around 30 students > > - limited Internet: the university network was much too slow for us to > > work with, we were given a special network bought for the school but the > > data was limited (we had to buy extra data a few times during the week) > > - every student had his / her own laptop. Only PCs, most of them Windows, > > 2 or 3 linux (Ubuntu) > > - most students had very limited computer skills > > > > Because of the Internet limitation, SMC was no good solution for everyone > > to use. We still used it to do some demos, share code, and also as a backup > > options for the students who couldn't get Sage running. > > > > Sage installation: > > > > Most of the students didn't have Sage installed, so the first afternoon > > was devoted to install Sage everywhere. It mostly worked but we sometimes > > had issues: > > * hard drive limitations: some hard drive were completely full and VM + > > Sage was too big to get installed (also their HD was often partitioned in > > weird ways and the program partition was full) > > * for some reason, the Sage VM takes forever to load on Windows 8 (which > > makes it seem broken) > > > > Using Sage on the VM: > > > > Never had so much Sage on Windows experience before, this was a good test > > and now here's everything that was wrong and annoying: > > > > * Once a Sage virtual machine was in "saved" mode, it would usually crash > > on re-openning and we had to discard the saved mode (I guess because their > > computers were running out of memory) > > > > * Sharing files between the VM and Windows was NOT straightforward at all, > > the Sage explanation were not working (I think you need to change the > > usergroup in Ubuntu or something like this), at the end I just dropped the > > idea as I could not do it on all 30 machines at once > > > > * And I didn't manage to make them download any notebooks either, because > > the notebook wouldn't take https addresses, so actually I had no way to > > share notebooks with them!! (except on SMC) > > > > * pdflatex wasn't installed by default which for me was a real problem as > > I use it a lot to print combinatorial objects (thank you Jean-Baptiste for > > the ascii art on binary trees, it saved me a bit!). And because of internet > > limitations and the lack of Ubuntu knowledge from my students, it was not > > really possible to install it on all their machines (I mean the VM) > > > > * I couldn't get the VM to show multiple windows and not even multiple > > tabs. This was so annoying... Sometimes a student would click on a link on > > a notebook and there was no way of going back to where it was before... Or > > to open Internet on the VM to download the notebooks or something... > > > > To finish, one very good thing that we need to keep: the Help link on the > > notebook was great, the students were navigating on the different tutorials > > and this worked very well. > > > > Anyway, this list is here to remind us what we could do better. I don't > > mean to push anybody but now that we'll have full time developers, I > > figured this real life experience was very useful for us non-Windows-users > > to have (at the end, what's the point of having open source softwares if > > the people who really need it can't use it properly?) > > > > Also I want to say that despite all of this, the school went really well. > > The students were really happy to learn about Sage, they were the most > > enthusiastic and motivated students I ever had. Both Jennifer and I were > > able to do great mathematics and we had a wonderful time! > > > > If ever you're interested, my class material on combinatorics is here: > > > > https://www.lri.fr/~pons/en/eaump.php > > > > and the whole summer school material (including the previous week) is > > there: > > > > http://people.bath.ac.uk/masgks/EAUMP/ > > > > Best, > > > > Vivi > > > > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-devel+unsubscr...@googlegroups.com. > To post to this group, send email to sage-devel@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. 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