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Table of Contents
Getting started in CLIM & ESTIMR
You are probably reading this page because you are a new intern student, visitor, etc…
This page will help you survive your first steps at LSCE, at least survive the computers…
Reading this page will save your life (and a lot of time)!
Using your own computer at LSCE?
No need to try to connect your laptop to the LSCE wire network, it will not work!
The best you can do is use the eduroam or guest wifi network, if your office is close enough to one of the access points.
Warning! You can't connect directly to the LSCE servers from the wifi network. If you need to do that, you will have to connect to a server outside LSCE first, and then back to LSCE…
Accessing the LSCE intranet
Web site: https://intranet.lsce.ipsl.fr/
There is a lot of information available on the LSCE intranet, but you can only access it from a computer connected to the LSCE network
Everything about the LSCE servers (and other software and hardware information): https://intranet.lsce.ipsl.fr/informatique/en/orme/index.php
- Reading the mails with the webmail or Thunderbird
- As soon as you have a LSCE e-mail address, make sure it is added to the clim or estimr mailing list
Accessing the CEA saclay intranet
Web site: http://www-saclay.cea.fr/
You can only access it from the LSCE and CEA network! This intranet is the place where you can get information about:
Setting up your desktop computer
Everybody working for CLIM & ESTIMR gets a computer that can be connected to the LSCE network. Please take the time to read the instructions below, that may help make your life easier
Windows 7 computer
Read the notes (and follow the instructions) in Windows 7 notes, especially the Basic Windows 7 Configuration section
Getting administrator's rights
Make sure you know what you are doing and that you are not executing a virus asking you suspicious access rights!
If an application requests administrator's rights to install something or make changes to the computer, and you are sure it's not a virus, use the .\adminuser
account and the adminuser password you got when your computer was configured, or ask the system administrators.
Linux computer
There are different window managers available, each one with different settings: you should the Cinnamon window manager (xfce is a bit too basic, and Gnome is not very convenient for doing actual work, and uses too much CPU). You can select the window manager by clicking on the little cogwheel below the password field, on the login screen.
This is Linux, you are using it for work, you should be efficient, so you should be able to do most of your work by typing commands in a terminal. The true power is in the correct use of the command-line interfaces, rather than having to spend time finding where to click in the windows. You will find some Linux documentation below.
Using the root acount
Do not use the root account or privileges if you don't know exactly what you are doing!
Depending on what you need to do:
- run a single command with the root access rights
sudo command - become root in a terminal
sudo su - - use the root password when a program asks for it. Be sure the programs have legitimate reasons to ask for the root password!
Mac
Sorry, you are on your own, but it's soooo easy to use, right?
Accessing the Linux servers from your LSCE deskop
Linux or mac desktop
Just open a terminal and use ssh to connect to the appropriate server
Windows desktop
There should be an Asterix shortcut on the left side of your desktop. Double-click on it in order to open a window environment on one of the asterix servers. Each terminal you will open in this environment will run on the same asterix server. Use ssh to connect to an obelix server if you need to run something that will require more computing resources
Which Linux servers should you use?
There are lots of things you can do directly on your local Win7 or Linux desktop (displaying pdf, images, using a text editor, …), rather than directly on the servers. Never forget that your local desktop has access to the remote disks on the Linux servers.
Otherwise, use the appropriate Linux servers. The load balancing system will send you to the server that has currently the smallest load
- asterixN (
ssh asterix
, orssh asterix.lscelb
): use these servers for the usual day-to-day work (things that use less than 1 Gb, don't use 100% CPU for a long time) - obelixN (
ssh obelix
, orssh obelix.lscelb
): use these servers for interactive processes that will need more ram and/or CPU during a longer time - the batch system for really heavy duty programs
Determining the load of a Linux server
If the Linux server you are working on seems slow, or if you want to get an idea of the resources you are using, you should use the top
command
jypeter@obelix4 - ...jypeter - 46 >top top - 17:48:51 up 8 days, 23:43, 29 users, load average: 1.22, 1.38, 1.98 Tasks: 324 total, 2 running, 320 sleeping, 2 stopped, 0 zombie Cpu(s): 12.6%us, 0.0%sy, 0.0%ni, 87.4%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 32877756k total, 14706188k used, 18171568k free, 21372k buffers Swap: 33554428k total, 1628972k used, 31925456k free, 14105940k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 10193 mpeau 20 0 302m 4336 2272 R 100.0 0.0 7033:08 emacs 16504 mpeau 20 0 110m 2008 1228 S 0.7 0.0 0:00.13 tcsh 26344 dzhu 20 0 1635m 20m 3880 S 0.3 0.1 0:44.90 ipython 1 root 20 0 21448 1108 892 S 0.0 0.0 0:01.61 init [...]
The top lines give you some summary information about the system, but you should monitor the memory usage (VIRT
and RES
), CPU
and TIME
columns. By default, top
will will put the processes using the more CPU at the top (as shown above). You can see above that the emacs
text editor has clearly crashed, because it should not use 100% CPU for such a long time
If you type M
, the processes will be sorted my memory usage, as shown below
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 16092 jchang 20 0 8488m 8.1g 7912 R 99.6 25.9 1:41.38 idl 23256 pvait 20 0 232m 70m 2632 S 0.0 0.2 0:01.36 R 26344 dzhu 20 0 1635m 20m 3880 S 0.0 0.1 0:44.87 ipython 10619 astege 20 0 954m 9292 2664 S 0.0 0.0 0:40.67 gedit 1362 nslcd 20 0 442m 6056 2208 S 0.0 0.0 2:13.98 nslcd 16238 twang 20 0 128m 5068 2076 S 0.0 0.0 0:00.05 gconfd-2 10193 mpeau 20 0 302m 4336 2272 R 99.9 0.0 7024:13 emacs [...]
Other useful keys:
q | Quit |
c | Display the command line options of the running processes |
u | List only the processes of a specific user |
Which disks should you use?
Do not forget to clean your directories before you leave (ask your advisor what should be kept or cleaned)
Accessing remote disks
It is possible to access directly all the disks on the LSCE servers from your local Linux or Windows desktop
- Example path on the LSCE Linux server:
/home/scratch01/your_lsce_login
- Accessing the same path from a local desktop:
- Linux desktop:
/home/scratch01/your_lsce_login
- Windows desktop:
\\dfshost\dfs\scratch01\your_lsce_login
The home directory
- Location: the location depends on the machine you are connected to in the current terminal
- On the LSCE servers (asterixN, obelixN):
/home/users/your_lsce_login
- On a local Linux desktop (lsceNNNN):
/homel/your_lsce_login
- The configuration files of your Linux account are stored in this directory (use
ls -a
to see hidden files and directories). Ask your advisor if you should copy somebody else's configuration files- tcsh shell users:
.cshrc
and.login
- bash shell users:
.profile
and.bashrc
- emacs text editor:
.emacs
- Backup of the home directory on the LSCE servers: YES! Every night
- Put the most important sources/scripts/data/papers in this directory
- Do not put temporary files, or big data files that are available somewhere else in this directory!
- Your home directory will also be archived when your account is closed
- Quota: YES!
There is a limit to what you can store in your home directory. If you reach this limit, you may experience some seemingly random errors (can't connect to the servers, the new files have a 0 size, …)
> quota -s Disk quotas for user jypeter (uid 6369): Filesystem blocks quota limit grace files quota limit grace prolix3:/users/ 4658M 4883M 4981M 23503 0 0
The scratch directory
- Location:
/home/scratch01/your_lsce_login
- Backup: NO
- Use this directory for temporary and big data files
- The files older than 6 months (and possibly older than 1 month) will be automatically deleted if there is not enough free space. See the Scratch area section for more details
- Quota: NO
Project specific directories
- Location:
/home/some_project_name/your_lsce_login
- Ask your advisor if you should use a specific project directory and the technical details about it
- Use this directory for storing the (big) data files that you can't store in the home directory, and should not store in the scratch directory
- Backup: ask your advisor
- Quota: ask your advisor
Useful documentation for beginners
Linux/UNIX
- UNIX_doc_JYP.pdf: some basic Linux documentation. Make sure you read it!
- A list of the most useful commands
- A tutorial
- Useful Linux commands for working with (potentially big) text files (houchesa4_updated.pdf)
- An annotated reference card of the emacs text editor (emacs_jyp.pdf)
You can also check the Les fondamentaux du pôle de modélisation du climat de l'IPSL wiki page
NetCDF and file formats
- What are binary (binaire_jyp.pdf) and NetCDF (netcdf_jyp.pdf) files?
- Network Common Data Form (NetCDF) official page
- The different netCDF formats (and do not forget to use
ncdump -k data.nc
if you need to know the format)
- Climate Data Operators for manipulating NetCDF files (and some other formats)
- netCDF Operator (NCO) for manipulating NetCDF files
- NetCDF CF (Climate and Forecast) Metadata Conventions: this will help you understand the information you get when you do a
ncdump -h some_climate_data_file.nc
- Using Python to work with NetCDF data:
- Using the cdms2 module if you work with the UV-CDAT distribution
- Using the netCDF4 module
Getting help from the LSCE system administrators
Send a mail to: help-lsce@lsce.ipsl.fr
Accessing the LSCE servers from outside the LSCE
The only way to access the LSCE servers from outside LSCE is to connect first to the idefix1.extra.cea.fr gateway server. Unless you are on a machine that is outside LSCE, but still on the CEA network (e.g. one of the machines of the CEA computing center)
- Send a mail to help-lsce@lsce.ipsl.fr, and request an access to the idefix1 server
- Use ssh to connect to idefix1
- From a Linux/mac desktop:
ssh -A -X your_lsce_login@idefix1.extra.cea.fr
- From a Windows desktop:
- Text only: use Putty
- Text & graphics. This is more complex to set up, and you need to use one of the options below:
- use VirtualBox
- There is only a limited number of programs that you can run on idefix1, so you have to go from idefix1 to asterix, obelix or curie with on of the ssh commands below:
ssh asterix.lscelb
ssh obelix.lscelb
ssh your_tgcc_login@curie-ccrt.ccc.cea.fr
- It's possible to use only one line to to both ssh commands
- asterix:
ssh -A -X your_lsce_login@idefix1.extra.cea.fr -t ssh -A asterix.lscelb
- obelix:
ssh -A -X your_lsce_login@idefix1.extra.cea.fr -t ssh -A obelix.lscelb
- TGCC:
ssh -A -X your_lsce_login@idefix1.extra.cea.fr -t ssh -A your_tgcc_login@curie-ccrt.ccc.cea.fr
- You can define an alias in order to connect more easily to the machines:
- tcsh users: add the following line to your
~/.cshrc
configuration file
alias iasterix 'ssh -A -X your_lsce_login@idefix1.extra.cea.fr -t ssh -A asterix.lscelb
' - bash users:
- You should create and configure an ssh key, if you don't want to type your password each time you use ssh or scp: https://intranet.lsce.ipsl.fr/informatique/orme/ssh.php
- If you want more information about ssh
Copying files to/from LSCE
If you are on a computer outside LSCE and you need to transfer a file to/from LSCE, you need to make the transfer between your current machine and idefix1!
- Example from a Linux/mac desktop:
scp -p file_outside_lsce your_lsce_login@idefix1.extra.cea.fr:/home/scratch01/your_lsce_login/
- From a Windows desktop: use winscp
What next?
Ask you advisor, who has probably already told you everything that was listed above, so you did not really learn anything new by reading this page
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