"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 -- Ashley Pittman, Bath, UK. Padb - A parallel job inspection tool for cluster computing http://padb.pittman.org.uk
