Hi William, I have used combinat in the past for big research computations, but not very recently (and I think I might have brought down the machine at some point due to too much memory use). So as long as we can still use the machine when we have large computations, I am ok with your plan.
I might still have some data/programs on the machine that I have not backed up. Could you please be very specific what we need to do to get access when running large computations? We would need to log onto SMC and then e-mail you to move the process over? Best, Anne On 1/3/15 8:23 PM, William Stein wrote: > Hi, > > The computer combinat.math.washington.edu is down... again. Sort of. > It responds to ping requests, but I can't ssh in. > > I suspect that not a lot of people are actively using it lately, since > this is the second time it has gone down for over a week in the last 3 > months, and nobody (except my student Hao Chen), seems to have > noticed. > > I'm considering doing the following. I'll shutdown combinat > completely, reformat the disk, and set it up as a node of the > cloud.sagemath.com (SMC). It'll still have the amazing 64 cores and > huge (192GB) RAM. However, instead of login in directly to it, people > can email me to request that I move a particular SMC project to > combinat. It will then have access to expanded compute resources. > The advantage of this, is that it is much easier for me to maintain. > In particular, SMC has automated scripts to take care of using cgroups > to explicitly limit usage of compute resources by a given project, I > have extensive monitoring code in place so I know when things go down, > and I everything runs in virtual machines, so when there are problems > I can easily fix them in a few minutes remotely. Also, it's much > easier to grant fair usage to projects. As it is now with default > linux on combinat, basically any user can just bring down the computer > by using too much memory/disk/whatever, which is probably what > happened in this case (I don't know). > > Thoughts? > > Obviously, this may be a bit slower and the max memory will be less > (as things are in a VM) for specific research-level computations. > However, a working computer is way better than a regularly-crashing > computer, in my opinion. Also, given the weeks of downtime that > nobody (except Hao) notices, maybe people aren't using combinat at all > anyways, due to it being only a remote linux box. Personally, I > think SMC makes using remote Linux boxes much easier. > > -- William -- You received this message because you are subscribed to the Google Groups "sage-combinat-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel. For more options, visit https://groups.google.com/d/optout.
