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/scratch filesystem

Warning

Please take a look to our Backup Policy before start using Hyperion.

Usage

/scratch is a shared high performance storage that system provides access to large amounts of disk for short periods of time. It meant to be used as the work space for jobs.

Info

You should use it only to submit jobs from and to redirect all your I/O.

Everytime a new user account is created the system will also create a subdirectory under /scratch filesystem of the form /scratch/username.

Tip

By default /scratch directories only allow access it's owner. This access can be sahred either with chmod command or making use of Access Lists (ACLs).

Remember that /scratch filesystems are not meant to be used as a permanent storage solution. When the occupancy goes above 80% the BeeGFS filesystem shows a performance degradation that affects all users. The same applies with large numbers of small files, since the BeeGFS filesystem is not behaving ideally when dealing with high volumes of small files. Therefore, avoid having too many files (>1000) within the same directory.

Quotas

  • Disk usage: 2 TB
  • Max. files: 10 Million

Check your usage on /scratch:

Since the usage of the /scratch filesystem is limited for each user to 2TB. It may be useful to check your occupation.

Keeping in mind that Hyperion cluster features three BeeGFS filesystems mounted (/scratch, /home and /data), three aliases have been created in order to check the quotas corresponding to each filesystem, being these getquota-home, getquota-scratch and getquota-data:

$ getquota-scratch

Checking quota in /scratch filesystem for user username

Quota information for storage pool Default (ID: 1):

      user/group     ||           size          ||    chunk files
     name     |  id  ||    used    |    hard    ||  used   |  hard
--------------|------||------------|------------||---------|----------
    username  |  xxxx||   43.81 GiB|    2 TiB   ||   262281|  10000000

Warning

Remember that the number of files created in this filesystem is limited to 10.000.000