At UQAM

Disk space

/home

When logging in to any of our servers you will automatically land in your "home" directory.

Everything that is small and important, like scripts and programs, should be under your home!!! Because your home is backed up every 3 hours. You find more information about the backup  and how to retrieve it if need be under:  home backup

Everything else should go under your "data space" - see below.

Everybody who has an account on our internal servers has a home directory, which is the same(!) on all our internal servers. It is called:

    /home/username

If you are in another directory and would like to go back into your home directory you can do that with a simple:

    cd

'~' is a synonym for your home directory. For example:  cd ~

'~username' is a synonym for the home directory of user 'username'. For example:  cd ~username

Home quota

You can put up to 500 MB of data under your home. There is no limit for the number of files. You can check your current quota with the command:
     quota
For more information about the command see: quota

If you prefer to have your scripts and programs with your data, you can create with symbolic links from the places from which you want to access them to the place under your home where they really are. You can find a short info about the link command, 'ln', here : Link files

Data space

Since most users will have more than 500 GB of data the home is too small to store all of them. Therefore, every user also has one or more "data spaces" assigned to their account. You find the name of your (first) data space in the email you got about your account creation.

Under your data space you should put your data files, for example: model output, input and output of your scripts and programs, etc.

No general backup is done for the data under the data space. However, there is a possibility to have up to 1 TB of selected directories backed up once a week. Have a look at the following page to learn more: Data backup

There are no quotas for the data space. The data space is shared by everybody using the same filesystem (main base directory). So before putting more than ~5 TB on any filesystem, make sure there is enough space free! You can check the usage of any mounted filesystem with the command 'df'. For example:
    df -h /filesystem
If you see the usage of a filesystem is greater than 95% let me (winger.katja@uqam.ca) know, please!!!

/transfer

/transfer is only to be used to transfer files into or out of the internal servers to/from machines which are not accessible from the internal servers directly. After the transfer is finish, all files are to be removed from /transfer.

/transfer is the only filesystem which is accessible from all external servers (the hoppies) as well as from all internal servers.

All users have a directory on /transfer.

Memory

The memory is shared by all users using the same server. This is why we ask you not to use more than 64 GB in total at any given time. You can check the available memory with the command:
    free
You can check and monitor the usage of your own processes with the command 'top'. For example:
    top -u ${USER}     # You can use the command as is. The variable 'USER' is defined by default and set to your username.
Once 'top' opened press the key 'M' (capital) to sort the processes according to memory usage instead of CPU usage. Look the the column 'RES'.

CPU power

The CPU power is shared by all users using the same server. To see how many cores are available on a given server execute the command:
    lscpu
Look at the line "Core(s) per socket".

To see how many CPUs are currently in use you can also use the command 'top':
    top
Look the the column '%CPU'.

At the Alliance

If one needs a lot of CPU power (more than ~20 cores) or a lot of memory (more than 64 GB) one can also use the clusters of the Alliance.

You can find more information on the web and on the following wiki: The Alliance