File system

The /home filesystem

Marbits relies in a parallel filesystem (see Lustre below) to store all your data. Hence, the /home filesystem is very small (about 150 GB for all users) and your ~/ directory has to be small too. When activating your user account, a soft link is created such as /home/your-user-name that points to your personal directory in the lustre filesystem. Please, keep your home as lightweight as possible, with configuration files and not much more. Also, feel free to make as many soft links to the lustre filesystem as you want.

Quota on the /home filesystem

Your /home directory has a quota so as no one can take too much space by mistake and degrade the performance of the master node. Currently there is a soft quota, that will allow you to exceed its value during a grace period of 7 days. After that period you won’t be able to write any more files to your home volume. There’s also a hard quote that can’t never be exceeded.

  • soft quota: 4 GB
  • hard quota: 5 GB

Lustre filesystem

Marbits mounts a parallel filesystem (Lustre) that is shared among several HPC clusters and services within the CMIMA. It allows parallel access to data, providing high speeds, and also distributes data among several servers and the redundancy also protects them.

Additionally, there’s a tape backup strategy that makes nightly incremental copies of all data (except from /mnt/lustre/scratch.

The Lustre filesystem is not administered by Marbits, as it is a common resource for several CMIMA services. Please use it in a sensible way by following this guidelines:

  • Make your jobs write their output to /mnt/lustre/scratch. When the job has finished, move everything that you want to keep to your lustre user directory (~/your-user-name. It is a soft link to /mnt/lustre/bio/users/your-user-name). Failing to do so may degrade the backup service and your jobs could be killed by the monitor of the filesystem. Moving files from one location to another within the same filesystem is immediate, so there’s no excuse not to do it! NOTE: Files in /mnt/lustre/scratch older than 3 months will be automatically deleted by the system
  • Try to discard anything that you won’t really need. Storage space is expensive, and we are not alone anymore.
  • Compress all the files you can. Many programs accept *.gz files as input…

Quota on the Lustre filesystem

Currently the Lustre filesystem has 369 T of storage. Storage use by the users will be closely monitored by the lustre administrators. Please, adhere to the previously detailed guidelines.