Speaker
Mr
Alexander Kulyavtsev
(FNAL)
Description
dCache is a distributed storage system which today stores and serves
petabytes of data in several large HEP experiments. Resilient dCache
is a top level service within dCache, created to address reliability
and file availability issues when storing data for extended periods of
time on disk-only storage systems. The Resilience Manager
automatically keeps the number of copies within specified bounds by
adjusting the number of replicas of each logical file on different
units of disk hardware when files disk pool nodes are found to have
crashed, been removed from, or added to the system.
We presented design of the dCache Resilience Manager in the CHEP2006
report "Resilient dCache: Replicating Files for Integrity and
Availability". The present paper provides an update on further
development of Resilient Manager and experience in the production
deployment and operations in US-CMS T1 and T2 centers. The US-CMS T1
center substantially increased the size of their Resilient dCache and
added second group of resilient pools for merging short files with
production job output before storing files on tape. Two resilient pool
groups operate independently of each other and other pool groups
(tape-backed or volatile). A few more US-CMS T2 centers started to use
Resilient Manager to increase the integrity and size of their systems.
Based on experience with the Resilient Manager in US-CMS centers we
added new features to drain files from the pools for hardware
retirement and to avoid replication of files to the same pool host,
while improving the Resilient Manager's performance and manageability.
| Submitted on behalf of Collaboration (ex, BaBar, ATLAS) | dCache |
|---|
Author
Mr
Alexander Kulyavtsev
(FNAL)
