DEtector with Lepton, Photon, Hadron Identification
- central software

Frequently Asked Questions

Caution: This page is being rewritten. The informations on the batch system and batch jobs often refer to the non-existing NQS system and are obsolete. Other informations should be correct.

If you are facing a problem you cannot easily solve, write to us and we will try to provide you with an answer.
Also, if you are the expert and are flooded with questions, let us know and by publishing the questions here may be your life will get a bit easier...

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Porting your analysis code to Linux

DELPHI-Core mail archives
AFS (in DELPHI and elsewhere)
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Documentation collected by IT, in particular:
- Tutorials & introductions: PAW, HTML, Emacs
- Manuals, writeups, reference cards
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- Questions received at the Help Desk
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DELPHI-Offline main page
DELPHI Computing Tutorials: 4 July 1997, 31 October 1997

DELSHIFT usage
- Run-time problems
  Q. In my batch job I got thousands of error lines of the kind
```
              
 ***** ERROR in HRZOUT : An error has occured whilst writing data : ID=  1 
 ***** ERROR in HNTWRT : An error has occured for //NTUPLES : ID=  1 
 RZOUT . Request exceeds quota
              
            
```
  I had no problems in my previous jobs. What happened?
  A. The reason is an unfortunate choice of parameters to HROPEN, which prevents big files being output. Please have a look at a special page we have made.
  Q. In my batch job I got the following warnings:
```
              
 FZIDIA.  LUN=  11 BAD CONSTRUCTION
          IQUEST(1/2/3)=  -4       0       1
          IQUEST(11-) =   -4 201   0
 %PHDST-E-PHQUES, Bad constructs, maybe not a FZ-file
              
            
```
  On other samples my analysis job works without problems. What should I do?
  A. Normally it is a problem of a corrupted file on disk. Just clearing the file and re-staging normally helps. If you are not sure how to do it, please contact delphi-core.
- Link problems
  
  Q. Under AFS I compile libraries with personal pieces of code. Will it be possible to link these directly on SHIFT using compiler option
  -L/afs/cern.ch/user/h/hector/public/libraries...
  
  A. Yes, with the same syntax as usual. Of course you may use here the shell environment variables. Note that for machines where several versions of operating systems exist (HPUX9/HPUX10, OSF1 V3/V4) you may have to maintain several versions of libraries...
  Q. I have an undefined symbol fpclassify during the link step. Do you have an idea how to cure it?
  
  A. This is the punishment for not using the standard cernlib command. The suggested compiler/linker command sequence is:
```
              $XLF77 $ADDCOMP -o program.exe program.f $ADDLIB \
              `dellib skelana dstana vdclap phdst` \
              `cernlib mathlib packlib`
            
```
  Q. The loader complains about something called /usr/local/lib/rl.o. Huh?!?
  
  A. This is an obsolete piece of object code. You can safely remove any reference to it from your script. Read this.
- Available queues
  
  Q. What are the available queues on DELSHIFT?
  
  A. The basic queues are called xx_8nm, xx_1nh, xx_8nh and xx_1nd (for 8 minutes, 1 hour, 8 hours and 24 hours of normalised CPU execution time). There are also some other queues, both on DELSHIFT and on other clusters.
- Example job
  
  Q. I am new in DELPHI. Where can I find an example of the analysis job?
  
  A. Have a look at into the ~pubxx/public/jobexample/ directory on CERN AFS. The job there works without any changes on both DELSHIFT and LXBATCH. The README file provides simple instructions how to use it.
- Getting help
  
  Q. Again somebody has put his "golden hands" into ... (I wish I knew!), causing that my program, in which I didn't change anything, crashes since yesterday with a completely incomprehensible message. If somebody knew what happened and wrote simply how to cure it, I would be very grateful.
  
  A. We will try to investigate your problem, but it should be obvious that we need more details on your job... The best and simplest is to complete the report form.
AFS usage
- Getting file from backup
  Q. I have accidentally deleted a file - may I get it back?
  
  A. Yes, up to 1 year after - although it is really easy only for your home directory files, and only for the version from the previous day. The backup is done automatically every evening for all /afs/cern.ch/user/... directories. They are put in the directory /afs/cern.ch/ubackup/... - i.e. mimicking your normal home-directory name, but with ubackup rather than user.
  For example, if your login name is melanie, then in order to recover the Welcome.html file from your www directory, do:
```
              cp -p \
              /afs/cern.ch/ubackup/m/melanie/www/Welcome.html \
              ~/www/
            
```
  For more details on restoring files from AFS backup independently on their date and location, please see the recent CERN Computer Newsletter article on this subject. There is also an older, slightly obsolete article, but having helpful examples.
- Setting up a group (team/task) disk area
  
  Q. In our team many people use files created by the others. It would be more practical to have these files in one common area, rather than to remember for each case who is the author. Is this possible? Some of our files must not be accessible from the outside.
  
  A. The so-called AFS project-space is made just for that. Have a look here.
- Making directories visible from outside
  
  Q. When I ask for help with my job crashing, people tell me that they cannot read my script nor job output. I don't understand it, as both these files have the necessary permissions.
  
  A. For the AFS file to be visible by the others it is not sufficient to have correct standard Unix permissions - the directory itself must also have the AFS-specific permissions.
  All files in your root directory are visible only to you - and you should not change this.
  The standard way of storing files which you want to be read by the others is to put them in your public sub-directory. Also all further sub-directories created under public will be by default visible by everybody, so you may organise your files there.
  If you insist of having a directory on your root level, please follow the prescriptions given below for the www directory.
  As you have guessed, all files and sub-directories created within your private sub-directory will be visible only to you.
- Disappearing home directory
  
  Q. I can't access my home directory on HPPLUS. When I log on, I have the following messages:
  No directory /afs/cern.ch/user/m/melanie! Logging in with home = "/".
  Can you do something for me?
  
  A. This is normally a sign of problems with some AFS volume - the one containing your home directory. Normally it is resolved after a few minutes, so try again later. Sometimes it is more serious (disk crash) and it will take longer, with today files most probably lost.
  Anyway, from the message you quote it should be obvious that this is not a DELPHI software problem and nobody in DELPHI can do anything. You should have a look on CERN Computer Centre status, very possibly the information on what is going on and how long will it take is already there.
Files in home directory
- "Dot files" for networking
  
  Q. Which files do I need for easy saving the results from my DELSHIFT jobs and what should be their contents?
  
  A. For correct communication of DELSHIFT job with the submitting host the .rhosts file is indispensable. For every FTP transfer, either in batch or interactive, .netrc file is very handy.
  More informations (with examples) is available.

WWW
- Publishing WWW pages
  
  Q. I have created a WWW page in my ~/www directory on AFS, but all browsers say it does not exist. Both the file and the directory have read permissions for "others". What gives?
  
  A. As mentioned above, for the AFS file to be visible by a WWW server it is not sufficient to have the correct standard Unix permissions - the directory must have also set the AFS-specific permissions. Please check them by
  fs listacl ~/www/
  and if in the answer you see the line:
  system:anyuser l
  (lookup permission only - no read), or when there is no line with system:anyuser at all, then enter the command:
  fs setacl ~/www/ system:anyuser rl cern:nodes rl
  Checking again like above you should see this being accepted and both read and lookup permissions set.
  Look here for more ample informations.

DELPHI news
- Accessing the expired news items
  Q. I need to re-read the news item which existed a few days ago, but has apparently expired since. Is there any way that I can still find it?
  
  A. There are at present 2 ways of doing it.
  1. One is using the standard news page, but it requires the knowledge of a folder name of the news item you are interested in. If you do know that, select option "Search a string in the news". Then change the button "Active news" to "Archived and Active news" and in the next field enter the exact name of the folder (delete the asterisk, as the wild-cards are not allowed when searching archived news). Finally enter the search string and where it appears (in description=subject, author line or entire text). Note that the matching is very simple (just a string within single line).
  2. The other method can be done only on VAX. You should log to AXDEOF cluster (old VXDEL1) and enter the command NEWS. Once inside, issue the command SET ARCHIVE. If you don't remember the folder name (news group), do DIR/FOLDER and you will be shown all available folders. Then do DIR folder.name and browse through the list of all items (you may limit the list by giving the author and/or the subject - see the online HELP). Once you find the requested item, just enter its number - it will be displayed. You may save it be entering EXTRACT file.name . When you finish, enter EXIT to quit the VAXNEWS program.

Miscellaneous
- Printing at CERN
  
  Q. Which printers can we use at CERN and what is the best print command (lp/lpr doesn't quite work)?
  
  A. CERN has developed own printer commands (usually called xprint or such). Please see here for a compilation of available printers in main areas of our experiment and commands to be used.

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JvE / RG / US, February '98 (and continuously since then...)

DEtector with Lepton, Photon, Hadron Identification - central software

Frequently Asked Questions

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DEtector with Lepton, Photon, Hadron Identification
- central software