Thank you. Ashley, for clarification between sudo and su. I live in a sphere of ignorance, but I feel I am slightly enlightened.
Regards, Tena On 2/14/11 1:39 AM, "Ashley Pittman" <ash...@pittman.co.uk> wrote: > > "sudo" and "su" are two similar commands for doing nearly identical things, > you should be running one or the other but there is no need to run both. > "sudo -s" is probably the command you should have used. It's a very common > mistake. > > sudo is a command for allowing you to run commands as another user, either > using your own or no password. su is a command to allow you to run commands > as another user using their password. What sudo su is doing is running a > command as root which is then running a shell as root, "sudo -s" is a much > better way of achieving the same effect. > > Ashley. > > On 13 Feb 2011, at 22:16, Tena Sakai wrote: > >> Thank you, Ashley, for your comments. >> >> I do have a question. >> I was using 'sudo su' to document the problem I am running >> into for people who read this mailing list, as well as for >> my own record. Why would you say I shouldn't be doing so? >> >> Regards, >> >> Tena >> >> >> On 2/13/11 1:29 PM, "Ashley Pittman" <ash...@pittman.co.uk> wrote: >> >>> On 12 Feb 2011, at 14:06, Ralph Castain wrote: >>> >>>> Have you searched the email archive and/or web for openmpi and Amazon >>>> cloud? >>>> Others have previously worked through many of these problems for that >>>> environment - might be worth a look to see if someone already solved this, >>>> or >>>> at least a contact point for someone who is already running in that >>>> environment. >>> >>> I've run Open MPI on Amazon ec2 for over a year and never experienced any >>> problems like the original poster describes. >>> >>>> IIRC, there are some unique problems with running on that platform. >>> >>> >>> None that I'm aware of. >>> >>> EC2 really is no different from any other environment I've used, either real >>> or virtual, a simple download, ./configure, make and make install has always >>> resulted in a working OpenMPI assuming a shared install location and home >>> directory (for launching applications from). >>> >>> When I'm using EC2 I tend to re-name machines into something that is easier >>> to >>> follow, typically "cloud[0-15].ec2" assuming I am running 16 machines, I >>> change the hostname of each host and then write a /etc/hosts file to convert >>> from hostname to internal IP address. I them export /home from cloud0.ec2 >>> to >>> all the other nodes and configure OpenMPI with --prefix=/home/ashley/install >>> so that the code is installed everywhere. >>> >>> For EC2 Instances I commonly use Fedora but have also used Ubuntu and >>> Solaris, >>> all have been fundamentally similar. >>> >>> My other tip for using EC2 would be to use a persistent "home" folder by >>> renting a disk partition and attaching it to the first instance you boot in >>> a >>> session. You pay for this by Gb/Month, I was able to use a 5Gb device which >>> I >>> mounted at /home in cloud0.ec2 and NFS exported to the other instances, >>> again >>> at /home. You'll need to add "ForwardAgent yes" to your personal >>> .ssh/config >>> to allow you to hop around inside the virtual cluster without entering a >>> password. The persistent devices are called "Volumes" in EC2 speak, there >>> is >>> no need to create snapshots unless you want to share your volume with other >>> people. >>> >>> Ashley. >>> >>> Ps, I would recommend reading up on sudo and su, "sudo su" is not a command >>> you should be typing. >> >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> http://www.open-mpi.org/mailman/listinfo.cgi/users
