Storage Notes

dCache Scratch

The dCache scratch area (the volatile, non-tape backed portion of dCache) which is used for temporary file storage has the following characteristics:

Size 253 TB
Erasure Policy/Algorithm LRU (Least Recently Used)
Pools 7
Pool Sizes 43 TB
Dash board
Pool Use by Group (PublicScratchPools are the volatile)
Max Concurrent Connections 1610
Max gridftp transfers 700
Max dcap transfers 210
Max any other protocol transfers 700

Note: When maximum number of transfer slots for a protocol are hit, new transfers are queued until the number of running transfers goes back below the max.

Bluearc Central Disk

The Bluearc based central disk which provides the various /nova/data /nova/ana /nova/app /nova/prod volumes has the following characteristics:

Size 343 TB (NOvA Assigned)
Erasure Policy/Algorithm None
Max Concurrent Connections (experiment) 5
Max Bandwidth (in/out) 200 MB/s (1.6 Gbit/s)
Locking Threshold 1 MB