hosts.fs.local - Local host information for StorageTek QFS shared file systems
∕etc∕opt∕SUNWsamfs∕hosts.fs.local
SUNWqfs
SUNWsamfs
A ∕etc∕opt∕SUNWsamfs∕hosts.fs.local file
can reside on each
host system included in the StorageTek QFS shared file system.
This file is used in conjuntion with the shared hosts
file, which resides in the shared file system and is
initialized by sammkfs (1m) from hosts.fs (4),
to initialize network connections between the hosts
of a shared file system.
For more information,
see the hosts.fs (4) and samsharefs (1m) man pages.
The StorageTek QFS shared file system daemon uses
the ∕etc∕opt∕SUNWsamfs∕hosts.fs.local file
and the shared hosts file present in the file system
during initialization and reconfiguration to determine
the server interfaces to which it should attempt to connect.
Its function is to restrict the server interfaces to which each
client connects.
The fs portion of the name must be the family set name
of the StorageTek QFS shared file
system as specified in the mcf file. For more information on
the mcf file, see the mcf (4) man page.
Each line in the hosts.fs.local file
corresponds to a possible metadata server.
Each line contains the following fields:
Field 1: host name
This field contains the name of a potential metadata server host to which the local host can connect. This field must match the first field of the host in the shared hosts file. You can use the
samsharefs (1m) command to verify the content
of the fields of the shared hosts file.
Field 2: host IP addresses
A comma-separated list of host IP names or addresses. This should be a subset of the second field from the same hosts entry in the shared hosts file.
The hosts.fs.local file is typically generated
by copying the shared file system's shared hosts file to
∕etc∕opt∕SUNWsamfs∕hosts.fs.local on each host.
Each line referring to a non-server host is then deleted,
and the third through fifth fields in the remaining lines
are deleted.
The network topology of the hosts is then examined in
conjunction with the file, and the server interfaces that
the local host should not attempt to connect to are removed
from the second field. When all of these have been removed,
the file is written out.
The samd (1m) command is then used to cause any
configuration changes to take effect.
During startup and file system reconfiguration,
the sam-sharefsd (1m)
daemon attempts to connect to the server host.
To do this, it searches the shared hosts file for the server's
identity, and it extracts the list of IP names and addresses from
the server's shared hosts file entry.
The daemon then looks up the server's name in the file system's
local hosts file, if any.
If a local hosts file does not exist, the daemon uses the
list from the shared hosts file.
If the local hosts file does exist, then the corresponding
list of host addresses is found in the local hosts file,
the two lists of host addresses are searched (lexically) for
common entries, and a common list is generated.
The ordering of the list is determined by the local hosts file
(left-most first).
The names or addresses in the common list are looked up and used
to attempt to connect to the server.
If an attempt fails, the daemon attempts using any remaining
addresses in order until all the addresses have been tried.
The following shared hosts configuration file supports
a configuration in which two potential servers share a
private interconnection and communicate to the other hosts sharing
the file system using a separate network. The examples in this section
show the hosts.shsam1.local files that can be found on the
various hosts.
# # shsam1 config, titan∕tethys servers, mimas∕dione clients # # This file goes in titan:∕etc∕opt∕SUNWsamfs∕hosts.shsam1, and # is used by 'mkfs -S shsam1' to initialize the FS meta data. # Subsequent changes to the configuration are made using # samsharefs (1m). # titan titan-ge,titan.xyzco.com 1 0 server tethys tethys-ge,tethys.xyzco.com 2 0 mimas mimas.xyzco.com 0 0 dione dione.xyzco.com 0 0
To ensure that titan and tethys always
connect to each other through
their private interfaces, titan-ge and tethys-ge,
each requires a hosts.fs.local (4) file.
To achieve this, files titan:∕etc∕opt∕SUNWsamfs∕hosts.shsam1.local
and tethys:∕etc∕opt∕SUNWsamfs∕hosts.shsam1.local
would contain the following lines:
# # shsam1 server local config, titan∕tethys servers, mimas∕dione clients # titan titan-ge tethys tethys-ge
To avoid the delays and inefficiencies of having mimas and dione
attempt to
connect to titan and tethys through the inaccessible,
private titan-ge and tethys-ge
interfaces, mimas and dione should also have
their own hosts.fs.local (4)
files. Files mimas:∕etc∕opt∕SUNWsamfs∕hosts.shsam1.local
and dione:∕etc∕opt∕SUNWsamfs∕hosts.shsam1.local contain
the following lines:
# # shsam1 client local config, titan∕tethys servers, mimas∕dione clients # titan titan.xyzco.com tethys tethys.xyzco.com
∕opt∕SUNWsamfs∕examples∕hosts.shsam1Contains an example of a hosts.fs file.
∕opt∕SUNWsamfs∕examples∕hosts.shsam1.local.server | ∕opt∕SUNWsamfs∕examples∕hosts.shsam1.local.clientContain examples of hosts.fs.local files.
