Hardware Reference
In-Depth Information
FIGURE 10.2: Certificate-based security. A client provides a user certificate
to a server, which looks up the user via LDAP to obtain credentials.
Linux Kernel Module. The most common OrangeFS interface, the Linux
Kernel Module leverages the PVFS protocol to minimize metadata in-
teractions and increase I/O throughput.
FUSE. The OrangeFS client interface for FUSE enables access to an
OrangeFS file system from a Mac.
MPI-IO. The ROMIO implementation of MPI-IO includes support
for OrangeFS, thus any MPI Library implementation that supports
ROMIO (i.e., MPICH and Open MPI) also has support for OrangeFS via
ROMIO. The MPI-IO interface bypasses the Linux kernel and provides
access to MPI-IO features not supported by POSIX standard interfaces.
Direct Interface. The Direct Interface allows user programs to directly
call the OrangeFS client library. It bypasses the Linux kernel for a more
ecient path to OrangeFS, providing high performance access for pro-
grams that are not written for MPI. This also allows access to file sys-
tem features not supported by the kernel. The Direct Interface is ac-
tually three layered interfaces that can be used by programmers (see
Figure 10.4). The top layer is the POSIX standard
stdio
interface in-
cluding
fopen()
,
fread()
, etc. The next interface contains the POSIX
standard system calls such as
open()
, and
write()
. The lower layer
contains OrangeFS specific calls such as
pvfsopen()
,
pvfsclose()
.
