On Tue, Jan 13, 2009 at 11:39 AM, ma...@mendelu.cz <ma...@mendelu.cz> wrote: > > Many thanks, memory seems to be a big problem on my server (I did > tests you suggested on my laptop and each worksheet is consumig a lot > of memory). I have seen that sagenb.org has 2GB memory - like my PC. > How many users wirk simultaneously on sagenb.org?
It has 2GB RAM and *10GB* swap. Having a lot of swap is critical, because as people leave worksheets running for a while, they can be swapped out without the machine getting into trouble. You have only 256MB swap, which is a recipe for disaster. Instead make it something bigger, e.g., a couple gigs at least. William > > * I think that I can set up my personal computer as second sage server > for my class > Is it sufficient to move the ~/login/.sage directory to clone > all the work to the second server? It should be. > > * I will ask our webmaster to increase memory on my virtual server on > Mondays :) > But it supprised me that sage is so memory demanding :( > The students were asked to calculate nothing more than few > limits and draw some 2d graphs. Sage demands a lot of memory because each worksheet launches its own Sage process. We could change Sage so that all users use exactly the same process. This would require way less memory, but would mean that if user X starts a calculation running, then Y starts another one, then Y would not see their result until X does. If X's calculation is factor(huge number) that would be annoying. 512MB is very very piddly for a server. > * Is there any other possibility how to decrease the memory demand? I > tried to open 17 notebooks with notebook(ulimit="-v 10240") but this > did not help. The demand for memory was the same as for notebook() > command. > > I wonder how the others use sage in education. Do they have so big > memory on their servers? > Thank you very much. > > Robert > > >> I noticed that for my Sage server, each open worksheet took about 140MB >> of RAM. When I ran out of memory, the server froze and lots of errors >> happened. To me, it sounds like you probably ran out of memory if you >> had 15 worksheets open simultaneously (which I would calculate would >> need about 15*140=2100 MB of RAM). >> >> You can test this yourself by opening up your notebook and opening up 15 >> worksheets in different tabs in your browser. Run a calculation in each >> one and check to see how much memory you have then. Also, you might see >> how much memory is consumed by running a single worksheet (i.e., check >> the memory usage, start up a single worksheet and calculate something, >> and then check the memory usage again). >> >> Jason > > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
