Versions Compared

Old Version 26

changes.mady.by.user Amedeo Perazzo

Saved on

compared with

New Version Current

changes.mady.by.user Amedeo Perazzo

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Space

Size

Backup

Lifetime

Storage class

Comment

xtc

Unlimited

Tape archive

6 months

Short-term

Raw data

usr

Unlimited

Tape archive

6 months

Short-term

Raw data from users' DAQ systems

hdf5

Unlimited

Tape archive

6 months

Short-term

Data translated to HDF5

scratch

Unlimited

None

3 months

Short-term

Temporary data

xtc/hdf5

10TB

n/a

2 years

Medium-term

Selected XTC and HDF5 runs

ftc

10TB

None

2 years

Medium-term

Filtered, translated, compressed

res

1TB

Tape

2 years

Medium-term

Analysis results

User home

20GB

Disk + tape

Indefinite

 

User code

Tape archive

Unlimited

Two copies

10 years

Long-term

Raw data

Tools

Web tools have been created to facilitate users in:

...

  • Applying processing framework to select useful events within a run (only when effective)

Rationale for Switching to New Policy

The goal of the new policy based on three different storage classes was twofold:

  • Allow users to have easy access (ie on disk) to the most frequently used data for a longer period of time
  • Make better use of the LCLS storage resources

We do believe this is a better policy, above all for the users. We noticed that the previous 1-year policy was not enough. At the same time keeping everything on disk for 2-years is not the best use of LCLS resources. Hence LCLS decided to extend the lifetime on disk to 2-years for the most used data files. This was done by introducing quotas and by letting the users select which files should stay on disk.

We do understand the new policy requires a more active participation by the users so we provided tools to help managing the data. For example, we made it much easier to restore data from tape and move data across storage classes.

Also, the scratch directories were sometimes (ab)used unfairly. So we decided to create three scratch areas (ftc, res and scratch) with different characteristics.

Frequently Asked Questions

...