Provided by: gfarm-client_2.4.1-1.1ubuntu1_amd64 
NAME
gfhost - Gfarm host maintenance command
SYNOPSIS
gfhost [ -H | -l | -M ] [ -iLprUv ] [ -P path ] [ -a architecture ] [ -D domain-name ] [ -j concurrency ]
[ hostname ... ]
gfhost -c [ -P path ] -a architecture -p port-number [ -n number-of-CPUs ] hostname [ host-alias ... ]
gfhost -m [ -P path ] [ -a architecture ] [ -p port-number ] [ -n number-of-CPUs ] [ -A ] hostname [
host-alias ... ]
gfhost -d [ -P path ] hostname ...
gfhost -R [ -P path ]
DESCRIPTION
gfhost is used to display and maintain information about filesystem nodes. The function that gfhost
performs is determined by an option, -c, -d, -H, -l, -M, -m, -R. These functions are mutually exclusive,
and only one option among them can be specified. If none of them is specified, host name will be
displayed as the default function of gfhost.
FUNCTIONS
Metadata in the metadata server will be accessed by function -c, -d, -M, -m or -R. These functions
add/delete/display/modify/restore host information in the metadata.
If -H, -l or -M is specified, or none of the functions are specified, gfhost displays filesystem node
information. The -M function only accesses information in the metadata server. Display functions other
than -M also access gfsd, which is running on filesystem nodes. For functions which access gfhost, the
access option can be specified by options -i, -j, -U and -v.
You don't have to specify hostnames for display functions. In that case, all hosts which are registered
in metadata will be displayed, but you can limit the type of hosts displayed by the -a or -D option. By
default, hosts are displayed in alphabetical order, but you can change this by the -L, -p, or -r options.
Although the -L option is ignored in the -M function and in the default function.
The following is a list of the functions of the gfhost command. You shouldn't specify more than one
functions at a time.
<none> If you don't specify any of the functions, gfhost accesses gfsd, and displays the names of hosts
which are currently available as its default function. Hostnames are displayed in alphabetical
order, by default.
-c Creates the metadata information for the host that is specified in the argument. Option -a is
mandatory for this function, this option specifies the architecture of the host. Option -p is
mandatory in this function too, this option specifies the port number of gfsd on the host. Option
-n may be used to specify the number of CPUs of the host, and 1 CPU is assumed, if -n is omitted.
You can specifiy multiple hostnames in this function. In that case, the first hostname is treated
as the identifier of the host, and the host identifier is used for replication information
management. The rest of the hostnames are used as aliases of the host.
If a host has multiple network interfaces, and each interface has a unique hostname, all of the
hostnames must be registered as either host identifiers or host aliases.
If /etc/hosts or the NIS hosts database doesn't contain a DNS domain name part in its hostnames
(i.e. these hostnames are not Fully Qualified Domain Names), you must register a host alias. In
that case, you must register FQDN (a hostname which contain a domain name part) as the host
identifier, and register names without the domain part as the host alias.
-d Deletes host information from metadata. Currently, even hosts which are referred by replica
catalog can be deleted. But be careful, because such deletions cause inconsistencies of metadata.
Only a host identifier can be used as a hostname in this function.
-H Displays load average and authentication method. With this function, the exact hostname passed by
the gfhost command arguments will be displayed instead of the canonical host identifier. Also,
this function displays the IP address used to access gfsd in parentheses just after the hostname.
If the host cannot be accessed due to a machine down or network problem, etc., x.xx/x.xx/x.xx will
be displayed in the load average field. If the host is up, but gfsd on the host cannot be
accessed, -.--/-.--/-.-- will be displayed.
The next field is the authentication method used with the host. `G' in this field means GSI
authentication and encryption, `g' means only authentication is performed by GSI and actual
communication is unprotected plain data (gsi_auth), `s' means gfarm sharedsecret authentication,
`x' means that the authentication failed, and `-' means that the authentication wasn't actually
tried. If the -U option is specified, this authentication method field won't be provided.
Hostnames are displayed in alphabetical order, by default.
-l Displays in the long format. This function displays both information retrieved from gfsd and the
metadata server. The types of information retrieved from gfsd are load average and authentication
method. And the types of information retrieved from the metadata server are architecture name,
number of CPUs, host identifier, and host aliases (if any). IP address will be displayed in
parentheses just after the hostname used for the access to gfsd.
If the host cannot be accessed due to a machine down or network problem, etc., x.xx/x.xx/x.xx will
be displayed in the load average field. If the host is up, but gfsd on the host cannot be
accessed , -.--/-.--/-.-- will be displayed.
The next field is the authentication method used with the host. `G' in this field means GSI
authentication and encryption, `g' means only authentication is performed by GSI and actual
communication is unprotected plain data (gsi_auth), `s' means gfarm sharedsecret authentication,
`x' means that the authentication failed, and `-' means that the authentication wasn't actually
tried. If that -U option is specified, this authentication method field won't be provided.
Hostnames are displayed in alphabetical order, by default.
-M The metadata information of the hosts will be displayed. Hostnames are displayed in alphabetical
order, by default.
-m Modifies metadata information of the host, by specifying the host identifier. The -a and -n
options overwrite the current value of each option. By contrast, host aliases will be added in
this function by default. If you want to replace or delete host aliases, please specify the -A
option with this function. In that case, all host aliases will be replaced by specified aliases
(if any).
-R Restores metadata information read from standard input. The format of the metadata is same as the
format that the -M function displays.
-? Prints usage.
OPTIONS
-A Alter. This option is used with the -m function to replace, rather than add, host aliases.
-a architecture
This option specifies the CPU architecture using a format like sparc-sun-solaris8 or
i386-redhat8.0-linux, etc. If this option is used with the -c or -m function, this means the
architecture used to add/modify the metadata information. If this option is used with -H, -l, -M
function or default function, this limits hosts to the specified architecture.
-D domain-name
This option is used with the -H, -l, -M function or the default function to limit hosts to the
specified domain.
-i There is an "address_use" directive in %%SYSCONFDIR%%/gfarm2.conf and $HOME/.gfarm2rc to give
priorities of network addresses for gfarm access. This directive works with the gfhost command,
but will be ignored, if you specified the -i option with gfhost.
-j concurrency
This option specifies the concurrency used for access to gfsd. The default value is 10.
-L Sorts by load average order. This option is effective only with the -H and -l functions.
-n number-of-CPUs
This option is used with the -c or -m function, and specifies the number of CPUs of the host.
-p port-number
This option is used with -c or -m function, and specifies the port number of gfsd on the host.
-P path
This option specifies a pathname or a Gfarm URL to identify a metadata server which will be
accessed by this command. If not specified, "/" is used as the default value.
-r Reverses the order of sort.
-u Plain order. This option stops sorting on the -H, -l, -M function or the default function. With
the -M function, command argument order (if any), or the order that the metadata server answers is
used for display. With the -H, -l function or the default function, the result is displayed in
the order that each gfsd answers.
-U Suppresses authentication attempts by TCP, and only queries load average by UDP. This option only
makes sense if you specified the -H or -l function, or if you didn't specify any function. This
option makes the gfhost command run faster. If the -H or -l function is specified, this option
makes the authentication method field disappear.
-v The -H, -l function and the default function don't produce error reports on gfsd accesses; these
error reports will be produced by this option.
SEE ALSO
gfarm2.conf(5), gfsd(8)
Gfarm 20 January 2010 GFHOST(1)