- Logging in
- HEC Filestore
- Some Notes on Panasas
- Copying files to the HEC
- Copying files from the HEC to the IUS
Once registered for an account you can connect to the HEC using any application offering support for secure shell (ssh).
- From the Interactive Unix Service (IUS) or any local linux desktop you
can access the HEC by typing the following in a session window:
ssh -X email@example.com
- From a local Windows PC the HEC can be accessed using any ssh (secure shell) capable application using the same hostname: arcadia.hec.lancs.ac.uk. Managed PC builds come pre-installed with the PuTTY application to enable ssh connections.
- For Windows PC users who wish to use application on the HEC which require graphics, please see the instructions on how to install and use cygwin
When logging in for the first time you may see the following message:
Host key not found from the list of known hosts. Are you sure you want to continue connecting (yes/no)?
Reply yes to the question and you will then be prompted for your password. This will be the same as your Windows or IUS password.
When you next log in you will only be prompted for your password.
You will have an allocation of home filestore on the HEC's Panasas fileserver. This is separate from your allocation on IUS or any other service. The default quota allocation for home directories is 2 Gigabytes, which can be increased on request if necessary.
The full path to your home directory on the HEC fileserver is of the form:
where NN is the same 2 digit number which appears in the path to your IUS filestore. Your home directory is recorded in your shell's HOME environment variable - type the command echo $HOME to view it.
There are also two other user filestore spaces available; storage and scratch. The paths to these directories can be determined by taking the path to your home directory (above) and replacing `/home' with `/storage' or `/scratch' respectively. For convenience, users can refer to their own storage and scratch spaces using the labels $global_storage and $global_scratch. Please Note: These labels cannot be used within job setup directives in bsub scripts.
Users' storage space is - like the home directory - subject to a quota, with an initial allocation of 20 gigabytes. Unlike the home directory, files placed in storage space are not backed up; users should store vital files in their home directory.
The third user filestore area - scratch - is not subject to quota. Users may use as much space as is available on the volume - up to 5 terabytes. Scratch space is not backed up, and files stored there are subject to deletion after 14 days. Please note: the scratch area is shared by all users - please use it responsibly.
You may view your home and storage quota details at any time using the command panquota.
On the Panasas filesystem, each file incurs an overhead which is taken from a user's quota. In the case of small files, this overhead is relatively high - some 128 Kb per file, even if it contains only a few bytes. Generating a large number of very small files can thus very quickly exhaust a user's file quota.
Best practice is to avoid generating large numbers of small files wherever possible. Where not possible, project directories and their contents should be archived using a tool such as tar as soon as project work is finished.
Files may be copied from the IUS into your HEC filestore by using the command scp on the IUS.
First, log in to the HEC and create a directory to receive the files. Suppose you call this directory my_project_files. Then on the IUS change to the directory which contains the files you want to copy and then type, for example:
scp * arcadia.hec:my_project_files
This will copy every file in the current directory on the IUS to the directory my_project_files on the HEC.
The first time you use scp it may prompt you with the following:
Host key not found from the list of known hosts. Are you sure you want to continue connecting (yes/no)? yes
Reply with yes and you will then receive a prompt for your password. Thereafter you will only have to give your password.
To copy any subdirectories and their contents, use the -r option to the scp command:
scp -r * arcadia.hec:my_project_files
Copying files from the HEC to the IUS is most easily done by running scp ON THE HEC
To copy all the files in the current directory on the HEC to a directory my_project_files on the IUS type in your HEC login session:
scp * ius.lancs.ac.uk:my_project_files
Transferring files between the HEC and a local desktop PC requires your PC to run a client application capable of the secure file transfer protocol. There are several applications available, and PC Managed Builds come with PuTTY and WinSCP pre-installed. For those without a Managed Build, the application installer can be found at \\lancs\software\Free\software\misc\winscp
Note: Take care to ensure that text files are transferred in text mode in order to avoid problems caused by format differences between Unix and Windows text files. Binary files (ie files whose contents are not solely ASCII text) should be transferred in binary mode