nokillprocess
disables the killing of processes that have written data to a
DVS server when a server fails. When a server fails, processes that have
written data to the server are not killed. If a process continues to perform
operations with an open file descriptor that had been used to write data to the
server, the operations fail (with
errno
set to
EHOSTDOWN
). A new open of the
file is allowed, and subsequent operations with the corresponding file
descriptor function normally.
●
Default setting:
killprocess
or
1
●
Associated environment variable:
●
Additional notes: If DVS periodic sync is enabled, DVS servers attempt to
fsync
dirty files to minimize the number of processes that are killed. DVS
periodic sync will also
fsync
a file's data when the file is closed. While it
is highly unlikely, if DVS periodic sync is not enabled, DVS cannot fully
guarantee prevention of silent data loss with this option alone because a
close()
does not guarantee data has been transferred to the underlying
media (see the
closesync
option).
loadbalance
/
noloadbalance
For a description of loadbalance mode, see
page 152.
noloadbalance
automatically sets the following mount options:
maxnodes
= 1
,
cache = 1
, and
hash_on_nid = 0
.
●
Default setting:
noloadbalance
or
0
●
Associated environment variable: none
●
Additional notes: none
magic
magic
defines what the expected file system magic value for the projected file
system on the DVS servers should be. When a DVS client attempts to mount
the file system from a server, it verifies that the underlying file system has a
magic value that matches the specified value. If not, the DVS client excludes
that DVS server from the list of servers it uses for the mount point and prints a
message to the system console. Once the configuration issue on the DVS
server has been addressed and the client mounts the correct file system, DVS
can be restarted on the server. All clients subsequently verify that the server is
configured correctly and include the server for that mount point. Many file
system magic values are defined in the
/usr/include/linux/magic.h
file. Commonly used magic values on Cray systems are:
NFS
0x6969
GPFS
0x47504653
Lustre servers
0x0bd00bd1
Lustre clients
0x0bd00bd0
●
Default setting: the underlying file system's magic value
Cray DVS
S3016
147
