Dirac on a vm at cern

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Work in progress! Use at your own peril!

Launching a virtual machine at CERN

  • Use openstack at CERN.
  • Change "Current Project" to your username.
  • Click on "Instances" and then on "Launch Instance"
  • Upload public ssh key (cut and paste will do), if not already done so, in the Access & Security tab
  • Choose "Any Availability Zone", "m1.medium" and "Boot from Image"
  • As image I am currently trying "SLC6 Server x86_64" (diractest2) and "SLC6 CERN Server x86_64" (diractest)
  • Click "Launch"

Claiming all your space

The virtual machine should come with 40GB, but the image doesn't expand correctly (this explanation is purposefully vague ;-) You probably see something like this:

[root@diractest2 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                      8.0G  2.2G  5.5G  29% /
tmpfs                 2.0G     0  2.0G   0% /dev/shm
/dev/vda1             388M   34M  334M  10% /boot

To claim all your space do:

growpart -N /dev/vda 2
growpart /dev/vda 2
reboot

After a successful reboot do:

pvresize /dev/vda2
lvresize -l +960 -r /dev/mapper/VolGroup00-LogVol00

and you should see all the space in VolGroup00-LogVol00 now.

Getting a hostcert for a virtual machine

  • Once the machine is up and running, you can log on as root via lxplus.cern.ch
  • Go to the new CERN CA
  • Click on "New host certificate". If it whinges about having to see your cert, ignore it, it will ask for it sooner or later. Your user cert should be in your browser at that point though. Click again on "host cert". This time hopefully it works. Under "Host selection" you should find your virtual machine. Click "Request".
  • Run the command it gives on your virtual machine and paste the output back (i.e. follow the instructions given on the webpage)
 openssl req -new -subj "/CN=diractest2.cern.ch" -out newcsr.csr -nodes -sha512 -newkey rsa:2048

This should take you to a page "Certificate issued". Follow the instructions.

  • Make a backup and save it somewhere other than your virtual machine:
     openssl pkcs12 -export -inkey privkey.pem -in host-diractest.cert -out diractest.p12 
  • Place hostcert.pem and hostkey.pem (= privkey.pem) in /etc/grid-security and change the permissions: chmod 400 hostkey.pem

Setting up the CAs

Setting up a UI

(Let's go with EMI3, even though we will need the EMI2 vomsclients.)

  • Get the repos:
  (if epel is not present:)
  wget http://www.nic.funet.fi/pub/mirrors/fedora.redhat.com/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
  rpm -i epel-release-6-8.noarch.rpm
  wget http://emisoft.web.cern.ch/emisoft/dist/EMI/3/sl6/x86_64/base/emi-release-3.0.0-2.el6.noarch.rpm
  yum localinstall emi-release-3.0.0-2.el6.noarch.rpm 
  
  • epel needs to have priority over the system repos, otherwise the install fails with "emi.saga-adapter.isn-cpp-1.0.3-1.sl6.x86_64 (EMI-3-base) Requires: libxerces-c-3.0.so()(64bit)"
  •  yum install emi-ui 
  • Get the EMI2 voms clients
yum shell
list *voms*
erase voms-clients3.noarch
install voms-clients.x86_64
run
exit
  • Make sure fetch-crl is turned on:
chkconfig --list | grep fetch-crl
chkconfig fetch-crl-cron on
service fetch-crl-cron start
  • Trying to get away without running yaim (note, you'll need the vomsdir one way or the other, even if it's doubtful you actually need the whole UI)
cd /etc/grid-security
wget http://www.hep.ph.ic.ac.uk/~dbauer/dirac/vomsdir.tar
tar -xf vomsdir.tar
cd /etc
wget http://www.hep.ph.ic.ac.uk/~dbauer/dirac/vomses.tar
tar -xf vomses
(there's something missing here, but I'll get to it)

Last minute prep

  • Remove mysql/mysql-libs from the node.
  • Now go to the Imperial dirac instructions and good luck....
  • Note that the VMs at CERN are not open to the outside world, unless by special dispensation. The only way to test job submission etc is to have the jobs run at cern. This snippet (to be inserted in the Sites section) allows you to run jobs at CERN, but I haven't worked out the SE bit yet.

     LCG.CERN-TEST.ch
      {
        CE = ce403.cern.ch
        CE += ce404.cern.ch
        SE = CERN-disk
        Name = CERN-PROD
        CEs
        {
          ce403.cern.ch
          {
          # these parameters seem to get overwritten somewhere 
            wnTmpDir = /tmp
            architecture = x86_64
            OS = CentOS_Final_6.4
            SI00 = 2125
            Pilot = True
            CEType = CREAM
            SubmissionMode = Direct
            Queues
            {
              cream-lsf-grid_dteam
              {
                maxCPUTime = 2880
                SI00 = 2125
                MaxTotalJobs = 4000
                VO = dteam
              }
            }
          } # ce403.cern.ch
         ce404.cern.ch
          {
            wnTmpDir = /tmp
            architecture = x86_64
            OS = CentOS_Final_6.4
            SI00 = 2125
            Pilot = True
            CEType = CREAM
            SubmissionMode = Direct
            Queues
            {
              cream-lsf-grid_dteam
              {
                maxCPUTime = 2880
                SI00 = 2125
                MaxTotalJobs = 4000
                VO = dteam
              }
            }
          } # ce404.cern.ch 
         } # CEs
        } # LCG.CERN-TEST.ch

Note that while you cannot run jobs outside CERN from a dirac instance made on a CERN VM, you can access outside storage, as long as you only require an outgoing connection. Writing to CERN storage (at least the one available for dteam) fails 4 out of 5 times with a timeout problem, there is not much you can do about this. Here's a snippet for the CERN disk.

   CERN-disk
    {
      BackendType = castor
      DiskCacheTB = 20
      DiskCacheTBSave = 20
      AccessProtocol.1
      {
        Host = srm-public.cern.ch
        Port =  8443 # apparently this can't be found automatically ?                                                
        ProtocolName = SRM2
        Protocol = srm
        Path = /castor/cern.ch/grid/dteam/
        Access = remote
        WSUrl = /srm/managerv2?SFN=
      }
    } # cern-disk   
  • My current best effort config files for a throw way dirac server at CERN can be found here.

Go back to the Dirac overview page.