Speaker
Alexander Mazurov
(CERN)
Description
CASTOR provides a powerful and rich interface for managing files and pools
of files backed by tape-storage. The API is modelled very closely on that of
a POSIX filesystem, where part of the actual I/O part is handled by the rfio
library. While the API is very close to POSIX it is still separated, which
unfortunately makes it impossible to use standard tools and scripts straight
away. This is particularly inconvenient when applications are written in
languages other than C/C++ such as is frequently the case in web-apps.
Here up to now the only the recourse was to use command-line utilities and
parse their output, which is clearly a kludge.
We have implemented a complete POSIX filesystem to access CASTOR using FUSE
(Filesystem in Userspace) and have successfully tested and used this on SLC4
and SLC5 (both in 32 and 64 bit). We call it CastorFS. In this paper we
will present its architecture and implementation, with emphasis on
performance and caching aspects.
Authors
Alexander Mazurov
(CERN)
Dr
Niko Neufeld
(CERN)
