SBND dCache storage » History » Version 3

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Gianluca Petrillo, 09/07/2017 02:30 PM

SBND dCache storage

dCache area consists of a huge data space, made of tapes and disks.
SBND owns one of each of two types of dCache areas. Each of them has room for areas owned by a single user:

  • scratch (/pnfs/sbnd/scratch/users/${USER}): files in this area can be deleted automatically; you can store a grid job result there waiting to transfer it into a safe place, but don't rely on leaving your important stuff there for long
  • persistent (/pnfs/sbnd/persistent/users/${USER}): files in this area will not be deleted

We have a limited quota of space as well, so fill it responsibly.

/pnfs/sbnd/persistent 25 TB (?)
/pnfs/sbnd/scratch ?

Remote access to dCache areas

While dCache areas may happen to be available on some local nodes (e.g., SBND GPVM's), in general the area is not directly reachable.
We use a tool called IFDH to fetch files from wherever they are. Also some code uses IFDH to fetch files: among them, LArSoft modules CORSIKAGen and GENIEGen.

IFDH sometimes requires the user to be authenticated, which is usually achieved by a certificate.
This is the same procedure as for getting credentials to submit jobs.