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Questions and Answers from the Computing Helpdesk

Collected by the User Assistance Team in IT/US

Nicole Crémel (Editor) , IT/User Services


Abstract

This is a collection of Questions & Answers that have been treated by the Computing Helpdesk managed by the User Services group.

N.B. The number in parentheses refers to its relative numbering in the "Question-Answer" database, at URL:
http://cern.ch/consult/qa/NNN
where NNN is the problem identifier (number).


 


Windows Support  -  


Question (QA 3185)   - NICE homeserver root directory

Examining my NICE homeserver root directory on the trustee manager, I discover that it is set to "Everyone - Read Only - This folder only". From another account, I discovered that I can see the names of my files!

I certainly don't want everyone to be able to read my root folder, so:
- how can I know who has set this access right?
- can I safely remove it, using the trustee's "remove - apply" options?

Answer   -   Don't remove it! This setting is essential and is the system default for all NICE root home directories. It is meant to be a traverse permission. Here is an extract of the user documentation on http://winservices.cern.ch (book "Windows 2000 at CERN"):
Traverse Folder allows or denies moving through folders to reach 
other files or folders, even if the user has no permissions for 
the traversed folders (applies to folders only). Traverse folder 
takes effect only when the group or user is not granted the 
Bypass traverse checking user right in the Group Policy snap-in. 
(By default, the Everyone group is given the Bypass traverse 
checking user right.)
Sounds very theoretical, so here is a practical example:
- you are user JOE on home server \\cernhome04
- you have granted everyone access to your PUBLIC subfolder
- another user tries to access it from 'start - run' by typing
  \\cernhome04\joe , or by going from 'My network places' into
  the relevant DFS folder, hoping (s)he will then be presented
  with the 'public' clickable subfolder location.
Here is where above 'everyone' permission is essential: it is only used to traverse your root folder, but does NOT mean another user can read the CONTENTS of it.

So, if you delete this permission, the user gets 'access denied' and will not be able to go further down the tree, unless (s)he uses the direct UNC \\cernhome04\joe\public

Note that some users have "NT authority/authenticated users" Read/Only rights to their home folder instead of the "Everyone" one. Both are equivalent in this respect.

Question (QA 3196)   - Do I have to reinstall W2000 when told so by support people?

I have quite some non-CERN applications installed on my NICE2000 PC. When I try to install CERN standard software on top of it from DFS (in my case Exceed), the installation fails regularly.

Support people suggest to re-install W2000 after having checked my PC. Do I have to follow their advice, or can I insist in having anything else tried? Uninstalling the OS would mean that I would lose my dozens of 3rd party applications and a long time to reinstall them again...

Answer   -   The User Support of central applications on the Windows platform is limited to personal computers owned by CERN, purchased via the PC-SHOP, installed with NICE2000, and for which the configuration has not been tampered.

If additional unsupported third party products installed by the user (in particular communication programs, internet browsers, mail clients, ISP disks) are suspected to be the origin of the problem reported to the helpdesk, the user may be requested to uninstall the third party products or reinstall the operating system before further investigation of the support staff can take place.

Related Links:

Question (QA 3202)   - Zephyr icon crossed out in red

It seems that the "Zephyr Notification Service" is not working properly on my Windows 2000 PC: when someone tries to send a Zephyr message to this PC it does not work and displays a red cross above the icon.

Answer   -   You get the 'red cross' over a Zephyr icon typically when you are:
  1. neither main user nor responsible i.e. administrator of the W2000 machine:
    Either register the user as one of them in the network database or ask the main user/responsible to add him/her to the list of local administrators.
  2. working offline.
Related links:

Question (QA 3228)   - Licences for applications on non-CERN computers

I have a PC that belongs to my home institute, and not to CERN. How shall I proceed to get applications installed from NICE?

Answer   -   Only computers which belong to and connect to the CERN Domain can receive software deployed by NICE group policy. The kind of installation you want is not only unsupported, but you will have to install whatever application you need at your home institute, as your PC belongs to them and not to CERN.

Therefore, a CERN licence for your computer will be refused.

Question (QA 3230)   - How can I see which application opens which file type on W2000?

How can I see which application opens which file type on my W2000 machine? For instance, which one opens my gif, jpeg, etc. files?

Answer   -   Select:
My computer - Control panel - Folder Options 
and then "File Types".

This contains a list of all file types known to your computer. To see which application opens which type, just click on the latter. The "Opens with:" field contains the associated application.

Related links:

 


UNIX Support  -  


Question (QA 2374)   - bin directory on Lxplus

It seems that my "bin" directory on Lxplus has disappeared and I can no longer execute commands which I have put there.

Answer   -   The "bin" directory on Lxplus (or all central machines based on AFS) is normally set up as a link to "@sys/bin" where the "@sys" variable is substitute by the OS value. You can check it with "ls -l bin" and you should get bin -> .@sys/bin .

Note: you can see the value of "@sys" on your system with the AFS command "fs sysname".

With the migration from Lxplus to lxplus7 (OS changed from Redhat 6 to Redhat 7.3) the AFS @sys variable has changed from i386_linux22 to i386_linux24. This means that under RedHat7 (and Lxplus) the "bin" directory points to:

bin -> .@sys/bin which is bin -> .i386_linux24/bin
However, with Linux Red Hat 7 (e.g. on Lxplus), the .@sys/... sub-directories (bin, lib, man, include, etc.) are not created by the CERN login scripts and you have to create them yourself with, for instance, the command:
mkdir -p $HOME/.i386_linux24/bin
(for bin) and copy the files that were into $HOME/.i386_linux22/bin into this new sub-directory.

Note: in case you have removed (by mistake) the file HOME/bin you can re-create the link with the command:

    ln -s @sys/bin $HOME/bin

Question (QA 3197)   - Tools (or software) missing on Lxplus (compared to lxplus6)

Since the migration of Lxplus to lxplus7 (with redhat 7) it seems that some tools (or software) are missing. Is it possible to put them back ? Whom shall I contact ?

Answer   -   With the new Redhat version on Lxplus only the tools and products that are part of the RedHat Linux 7.3 distribution are available. This means that some tools/commands that can be accessed on lxplus6 are not available anymore.

The Unix managers will add tools/commands only when there is a clear support. If you find a tool missing which is not included in the list below, please send a mail to it-div-fio-lxplus7@cern.ch (as suggested in the "message of the day" or MOTD at login). If the support can be defined the tool will be added. Otherwise it will be included in the list of "missing commands" with an explanation and possibly a replacement tool.

Related links:

Question (QA 3269)   - Exceed on Lxplus - login panel re-appears

Trying, on a Windows PC, to connect to Lxplus via Exceed (Start - Program - Hummingbird... - CERN Settings - Predefined X Connections - Lxplus) I get the login panel, manage to login with my usual password, but nothing happens and after a few seconds the login panel re-appears again.

Answer   -   Since the migration of Lxplus to Redhat 7 we have seen many users with similar problem, linked to their environment and due to the much stricter checking of user settings with the new Operating System.

Most probably the problem is linked with one of your shell login files (e.g. .tcshrc or .login) and the solution is to reset these files to something more "clean". You can do it by opening a connection (with ssh or Exceed) on lxplus6 instead of lxplus. From there you can reset your environment by executing the command "uco":

   uco
    1   - Setting your shell environment
   and
    1   - Reset the environment of your default shell
This will save a copy of your configuration files, and generate new files for your shell (you may then have to look in your old files to put back what is needed for you).

Related links:

Question (QA 3295)   - ~ character for AFS home directory does not work

I expect the command "cd ~ttttt/public" to put me in /afs/cern.ch/user/t/ttttt but I get instead the following error messages:

zsh: no such user or named directory: ttttt
or
ksh: cd: /afs/cern.ch/user/.../~ttttt/public - No such file or 
directory
I am on a private Linux PC.

Answer   -   In order to have the ~ character recognised, and have, for instance, the command "ls ~ttttt/public" to work, the login ttttt must be included in the local /etc/passwd file on your Linux PC.

Question (QA 3276)   - scp (for file transfer) - Write failed flushing stdout buffer

I try to transfer files from and to CERN from my external institute (outside CERN) using the secure command "scp" (scp xxxx@lxplus.cern.ch) but it fails with the following error:

 Write failed flushing stdout buffer.
 write stdout: Broken pipe
N.B. I have no problem to open a remote connection with ssh.

Answer   -   Most probably it is a problem with your environment and login scripts (.tcshrc .bashrc .cshrc .login .profile, or similar files, depending on your shell). Any message generated from your shell startup scripts can confuse "scp" (which uses "ssh" for the control channel) and it will usually abort.
Please note: before any message is generated in your login files, it should be (inside the script) surrounded by a check whether the shell is "interactive" or not.

In order to check whether this is the problem, and whether some messages are wrongly generated from your login scripts, try to execute the command:

  ssh xxxx@lxplus.cern.ch /bin/true
and see whether you get anything as output. If yes, you should look from which login files this output comes, and comment the lines that generate it (or put a test to check whether the shell is "interactive" or not). For instance you should comment the lines starting with "echo" or "env" that generate some output.

Remark: if the above command is indeed silent, then it means the problem is something else, and you should provide the output from the command "scp -v -v -v ..." and "nslookup lxplus.cern.ch for more debugging from the Unix system managers.

Related links:

 


Mail and Web Support  -  


Question (QA 3254)   - After the migration to Exchange

What is new after the migration to Exchange?
What do users have to know ?

Answer   -  

After migrating to Exchange the main advantages are the provided services, e.g. the improved SPAM fighting, the new mail web interface, the collaborative environment with the possibility to share the calendar / mail folders, and much more.

Other services provided are:
The "Out of office assistance"
E-mail forwarding
Send of behalf of someone
Instant messenger

This and more can be found at the MMM Services page .

When running Nice 2000 on Windows 2000, you have two choices (for supported clients):

  1. Use Outlook 2000 in Internet mode (IMAP connection)
  2. Install Office XP instead of Office 2000 and use Outlook XP (2002) (in MAPI connection).
For more information please have a look at this page:
http://cern.ch/mmmservices/Help/contents/0_1_outlook_advice.asp

If you decide to use Outlook 2000 then the only thing you will have to do (unless you filled it out during the migration) is to change the IMAP folder path under:
Tools --> Accounts --> Properties --> Advanced --> Remove the \mail root folder path.

For more information on how to configure Outlook 2000 please have a look at:
http://cern.ch/mailservices/docs/clients/outlook/settings/mail_manual.htm

If you decide to install Outlook XP then follow this link on how to configure the client: http://cern.ch/mmmservices/Help/contents/0_1_outlook2002.asp

When running on Unix (Linux, Solaris) you can:

  1. use Pine: then you have to use Pine 4.x.
    http://cern.ch/mmmservices/Help/contents/0_1_pine4.asp
  2. use a web mail client such as Mozilla.

Page concerning different e-mail clients page (e.g. Mozilla)
http://cern.ch/mmmservices/Help/contents/0_1_clients2.asp
To access the Exchange services such as:
The "Out of office assistance"
E-mail forwarding
Send of behalf of someone
Set permissions
Instant messenger
Spam fight (here you set your own Spam tolerance level)

Please have a look at the MMM Service Web site at:
http://cern.ch/mmmservices/Services

Related Exchange migration FAQ's

Question (QA 3070)   - How do I find out my mail server?

We sometimes are informed that one out of the many mail servers has problems, or will be down for some time.

How can I find out which of the CERN mail servers I am served by?

Answer   -   You can go to the web site http://cern.ch/mmm and open the link Where is my mailbox ? (under "Services"). Just type your mail login, and the information will be returned (this only works inside CERN).

Another solution is to use the command

nslookup xxx.mailbox

xxx being your mail loginid.

N.B. On a Windows PC, you can access this command by opening a cmd.exe window with:
Start - Run... - cmd

(Command is located in C:\WINNT\System32). and then execute nslookup xxx.mailbox

Question (QA 3084)   - Pine on Redhat 7 (Lxplus) - mail pre-authentication (password)

With the migration of Linux to Redhat7 it seems that I cannot open "pine" without being asked for the password.

Answer   -   This is a problem for people who have migrated to the Exchange mail servers (MMM service) - and it will be the case for all users in the future. A solution to that problem (to avoid to have to type the passwords for all your pine sessions) is:
  1/ touch $HOME/.pine.pwd
  2/ chmod 600 $HOME/.pine.pwd
  3/ start pine and enter you NICE password for the last time
  4/ say yes to the question 'Preserve password on DISK for next login?'
Related links:
  • pre-authentification when using pine (qa/456) at: http://consult.cern.ch/qa/0456
  • Question (QA 3227)   - Exchange migration - Moving AFS local folders

    I have been migrated to the new Exchange mail servers, but I am still using pine (pine4) on Unix. How can I move my local AFS folders on the new Exchange servers ?

    Answer   -   This is explained in the web page "Pine 4 configuration" and section "Moving your local folders ..." (at the end). You can access it: Please note: however, even after migration to Exchange, you can continue to use Pine with the new system as before, e.g. storing some mails in folders of the mail server, and some other mails in local folders. You will need to move all your local folders to the mail server if you want to get rid of Pine and use, for instance, Outlook XP on NICE (e.g. to benefit from the new calendaring feature).

    Question (QA 3151)   - Restore Internet Explorer's Favorites

    How do I recover my IE favorites after they have been reloaded from backup onto a NICE scratch location? Which local folder/path do I have to put them into?

    Answer   -   2 possible methods:
    1) - Stop the browser (all its windows)
       - Move the contents of C:\Documents and Settings\userlogin\Favorites to
         a temporary folder or directly to the recycle bin (logged
         in as Administrator!) 
       - Move the contents of the recovered Favorites folder to C:\Documents
         and Settings\userlogin\Favorites
       - Restart the browser.
    
    2) - Stop the browser
       - Drag the recovered Favorites folder directly with the mouse onto IE's
         Favorites field    
       - Restart IE.
    

     


    Computer Security  -  


    Question (QA 3166)   - Access CERN account from outside

    I am outside CERN and I would like to know how can I login to CERN ?
    (Either to access my NICE account from a Windows PC, or my Lxplus account from a Unix / Linux machine).

    Answer   -  
    1. Connection to Lxplus from outside CERN from a Unix machine:
      use ssh to open a remote and secure connection.
    2. Connection from a Windows PC:
      • either use PUTTy ( which is equivalent to SSH for Windows ).
      • or use the VPN service ("Virtual Private Network"),
      • the last solution would be to connect the same way as you do from home, i.e. using the ACB service ("Automatic Call Back").
    Related links:

    Question (QA 2436)   - Are you aware of this virus ?

    I have received a mail warning me about a virus that is not detected by Norton 2002 and Mcafee.

    Are you aware of this virus at CERN?

    Answer   -   Most probably the mail you have received is a HOAX, i.e. wrong information. Never send such mail to anybody but delete it immediately.

    All NICE 2000 machines at CERN are protected against viruses, and if a new virus would appear by accident you would get news and information from IT and the Computer.Security team.

    We expect that real viruses are either already in our anti-virus software or they make it to prime time TV/radio news...

    Related links:

    Question (QA 3296)   - Error from Norton anti virus about LiveUpdate packages

    Since a few days I am receiving a pop-up window on my Win2k system with an error from Norton AntiVirus:

     
     "Unable to determine which LiveUpdate packages to request"
     
    
    What is the recommended action?

    Answer   -   For LiveUpdate problems, it is not necessary to uninstall NAV.

    1) try simply rebooting the PC. Often the problem disappears afterwards.

    2) If it doesn't:
    Just go to Control Panel - add/remove programs and uninstall live update. Then go to \\cern.ch\dfs\Applications\Symantec\live update and install lusetup.exe


    About the author(s): Editing and revising the "Question and Answers" database is a daily task of the members of the User Assistance Team in the User Services group.


    For matters related to this article please contact the author.
    Cnl.Editor@cern.ch


    CERN-CNL-2003-001
    Vol. XXXVIII, issue no 1


    Last Updated on Mon Apr 14 10:45:43 CEST 2003.
    Copyright © CERN 2003 -- European Organization for Nuclear Research