Dima, William, On Mar 27, 8:42 am, Dima Pasechnik <[email protected]> wrote: > On Mar 22, 2:00 am, William Stein <[email protected]> wrote: > [...] > > > > > > I've tried usingskynetfor Solaris, but the machines are not very fast, > > > and heavily loaded sometimes. > > > You have to type > > > touch/tmp/`hostname`0 /tmp/`hostname`1 /tmp/`hostname`2 > > /tmp/`hostname`3 /tmp/`hostname`4 > > I tried this on mark, and got: > > bash-3.00$ touch /tmp/ > `hostname` > touch: cannot change times on /tmp/mark > > indeed: > bash-3.00$ ls -l /tmp/`hostname`* > -rw-r--r-- 1 wbhart sage 0 Oct 15 02:43 /tmp/mark > -rw-r--r-- 1 wstein sage 0 Mar 20 18:56 /tmp/mark0 > -rw-r--r-- 1 wstein sage 0 Mar 20 18:56 /tmp/mark1 > -rw-r--r-- 1 wstein sage 0 Mar 20 18:56 /tmp/mark2 > -rw-r--r-- 1 wstein sage 0 Mar 20 18:56 /tmp/mark3 > -rw-r--r-- 1 wstein sage 0 Mar 20 18:56 /tmp/mark4 > - > so this does not seem to be working as advertised - one has to be > root, or the users wbhart and wstein > should do appropriate chowns... > > Dima > > > to temporarily disable the ECM jobs running on a given node onskynet, > > which use spare cycles. (They will stop after a certain amount of > > time.) > > > William
On Skynet/mark, the reason why Dima could not touch /tmp/mark was because William already had touched (written) that file and so owned the file - and only William had read/write permission for his file. While William's suggestion of > touch/tmp/`hostname`0 /tmp/`hostname`1 /tmp/`hostname`2 > /tmp/`hostname`3 /tmp/`hostname`4 will put Skynet background jobs to sleep on most Skynet machines, it does not work on all (in particular on mark). For a list of the correct files to touch to put background jobs to sleep see on Skynet:/usr/local/README.background_jobs. All the background jobs on Skynet machines run at the lowest possible user priority, so other user jobs should get the majority of CPU time. Only if you really want to turn off the background jobs should you touch the appropriate file. Each background job periodically looks for its "sleep" file and puts itself to sleep as long as the sleep file exists. If you put a background job to sleep, please remember to remove your sleep file when you are finished. (Otherwise a periodic cron job will remove the sleep files.) Currently it seems that the background jobs on mark look for the sleep file every 40 minutes or so. (The time is a function of the inputs to the background job.) If this is unacceptable, let me know and I will change the inputs. The primary purpose of the Skynet machines is for Sage research. However I have a responsibility to the people who paid for these machines (the US taxpayers) to not have the machines sitting around idle. I hope you understand. Mariah -- To post to this group, send an email to [email protected] To unsubscribe from this group, send an email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org To unsubscribe from this group, send email to sage-devel+unsubscribegooglegroups.com or reply to this email with the words "REMOVE ME" as the subject.
