NAME

samsharefs - Manipulates the StorageTek QFS shared file system configuration

SYNOPSIS

samsharefs [-f host] [-h] [-o host] [-q] [-R] [-s host] [-u] fs_name

AVAILABILITY

SUNWsamfs

SUNWqfs

DESCRIPTION

The samsharefs command prints and modifies the host configuration for a StorageTek QFS shared file system. The printed hosts configuration identifies the metadata server and the client hosts included in the StorageTek QFS shared file system. This command is only valid from the metadata server or potential metadata server.

You create an initial hosts configuration file using vi (1) or another text editor. The sammkfs (1m) command reads this initial hosts configuration from ∕etc∕opt∕SUNWsamfs∕hosts.fs_name when the Oracle HSM shared file system is created.

To subsequently change the host configuration you must use the samsharefs command. Typically, you use an editor to edit the ASCII hosts configuration as printed by the samsharefs command and use the samsharefs command to update the file system host configuration.

OPTIONS

This command accepts the following options:

-f host

Marks host "off" in the hosts file. This option rewrites the on-disk hosts file and causes the Oracle HSM daemon to reread the hosts file. Marking the host off disallows that host to access the specified fs_name, and is reversed by using the -o option. -f is incompatible with -u parameter.

Marking a host client "off" allows that client to remain in the host file, but not access the specified file system. It is intended to be used to remove clients and not require the file system to be unmounted on all other clients. The removed host remains in the host file as a placeholder and can later be restored by using the -o parameter. Note that the client will need to be marked "off" from the metadata server for each file system that it mounts.

The host client's "on" or "off" status can be seen in the 4th column of the host file (as printed by the samsharefs command). For backwards compatibility, a "-", "0", or blank in this column indicates "on". Also, if a client is marked off, it is indicated by an "OFF" flag on the samu "g" display (or the samcmd g command).

CAUTIONS & LIMITATIONS: A file system that is to be shared to other clients must be mounted on the metadata server and also be mountable to potential metadata servers. Thus a client that is an actual metadata server cannot be marked off.

The only supported way to mark a client host off is to unmount its file systems and shutdown and halt the client. Then issue the samsharefs -f host fs command from the metadata server.

The only supported way to restore a client host is to mark the client host on (using the -o parameter) prior to booting that client. The client is then free to remount the affected file system.

Clients, while marked off, will not be able to contact the metadata server for that file system. If a marked-off client tries to contact the metadata server for that file system, its messages will be discarded and system hangs may occur. The result of trying to talk to a metadata server from a marked-off client is undefined and not supported.

-h

Writes a short usage message to stdout.

-o host

Marks host "on" in the hosts file. This option rewrites the on-disk hosts file and causes the Oracle HSM daemon to reread the hosts file. Marking the host on allows that host to access to the specified fs_name, and reverses the effect of the -f option. -o is incompatible with -u parameter. See -f option above for cautions & limitations.

-q

Suppresses host configuration output. By default, the command writes the file system host configuration, possibly modified, to stdout.

-R

Specifies that the file system's host configuration should be manipulated using the raw disk device associated with the file system, rather than the file system interfaces. This option can be used to change hosts information when the file system is not or cannot be mounted. This option can also be used to change hosts information when the file system is mounted, but the active metadata server is down.

CAUTION: This option must not be executed on a potential metadata server to change the metadata server host without first stopping, disabling, or disconnecting the active metadata server. Doing so will cause file system corruption.

-s host

Sets the server flag for the specified host in the system configuration. This option declares host to be the new metadata server host. All other hosts's server flags are cleared.

-u

Specifies that the file system's configuration is to be updated from ∕etc∕opt∕SUNWsamfs∕hosts.fs_name. When updating the configuration of a mounted file system, new host entries can only be added to the end of the existing configuration. If the server or any host's position differs between hosts.fs_name and the active configuration (i.e., the order of the hosts is changed), the command issues an error message and exits; changing these characteristics can be done safely only on an idle, unmounted file system. (See the -R option.)

fs_name

Specifies the family set name of the StorageTek QFS shared file system.

EXAMPLES

Example 1. The following example shows how to use the samsharefs to examine the hosts information on a mounted StorageTek QFS shared file system:

tethys# samsharefs share1
#
# Host file for family set 'share1'
#
# Version: 4    Generation: 14    Count: 3
# Server = host 0∕titan, length = 112
#
titan titan.xyzco.com 1 0
tethys tethys.xyzco.com 2 0
mimas mimas.xyzco.com 0 0

Example 2. The following example shows how the hosts configuration can be modified to add new hosts to the shared file system. The administrator has edited ∕etc∕opt∕SUNWsamfs∕hosts.share1 and added new hosts for the shared file system as shown. samsharefs is then run with the -u option to update the (mounted) file system's configuration.

titan# samsharefs share1
#
# Host file for family set 'share1'
#
# Version: 4    Generation: 14    Count: 3
# Server = host 0∕titan, length = 112
#
titan titan.xyzco.com 1 0
tethys tethys.xyzco.com 2 0
mimas mimas.xyzco.com 0 0
titan# cat ∕etc∕opt∕SUNWsamfs∕hosts.share1
#
# New share1 config, adds dione and rhea
#
titan   titan.xyzco.com 1 0 server
tethys tethys.xyzco.com 2 0
mimas   mimas.xyzco.com 0 0
dione   dione.xyzco.com 0 0
rhea     rhea.xyzco.com 0 0
titan# samsharefs -u share1
#
# Host file for family set 'share1'
#
# Version: 4    Generation: 15    Count: 5
# Server = host 0∕titan, length = 162
#
titan titan.xyzco.com 1 0
tethys tethys.xyzco.com 2 0
mimas mimas.xyzco.com 0 0
dione dione.xyzco.com 0 0
rhea rhea.xyzco.com 0 0

Example 3. The following example shows how the hosts configuration can be modified to change the StorageTek QFS shared file system server while the file system is mounted.

tethys# samsharefs -s tethys share1
#
# Host file for family set 'share1'
#
# Version: 4    Generation: 16    Count: 5
# Server = host 0∕titan, length = 162
# Pending Server = host 1∕tethys
#
titan titan.xyzco.com 1 0
tethys tethys.xyzco.com 2 0
mimas mimas.xyzco.com 0 0
dione dione.xyzco.com 0 0
rhea rhea.xyzco.com 0 0

Example 4. The following example shows how the hosts configuration can be modified to add a new StorageTek QFS shared file system server. Because the new server's entry is being inserted into the existing list rather than appended to the end, the file system must be unmounted on all hosts before executing this command, and the -R option must be specified. Note also that this command changes the file system server back to titan (from tethys).

tethys# samsharefs -R share1
#
# Host file for family set 'share1'
#
# Version: 4    Generation: 17    Count: 5
# Server = host 1∕tethys, length = 162
#
titan titan.xyzco.com 1 0
tethys tethys.xyzco.com 2 0
mimas mimas.xyzco.com 0 0
dione dione.xyzco.com 0 0
rhea rhea.xyzco.com 0 0
tethys# cat ∕etc∕opt∕SUNWsamfs∕hosts.share1
#
# New share1 config, adds server iapetus
#
titan     titan.xyzco.com 1 0 server
tethys   tethys.xyzco.com 2 0
iapetus iapetus.xyzco.com 3 0
mimas     mimas.xyzco.com 0 0
dione     dione.xyzco.com 0 0
rhea       rhea.xyzco.com 0 0
tethys# samsharefs -u -R share1
#
# Host file for family set 'share1'
#
# Version: 4    Generation: 18    Count: 6
# Server = host 0∕titan, length = 192
#
titan titan.xyzco.com 1 0
tethys tethys.xyzco.com 2 0
iapetus iapetus.xyzco.com 3 0
mimas mimas.xyzco.com 0 0
dione dione.xyzco.com 0 0
rhea rhea.xyzco.com 0 0

FILES

The hosts configuration for a StorageTek QFS shared file system is initialized from:

∕etc∕opt∕SUNWsamfs∕hosts.fs_name

This file is used at the time of file system creation by sammkfs (1m) and subsequently when the -u option is specified to samsharefs (1m).

NOTE

In Oracle HSM shared file system environments, archiving operations should be stopped on the metadata server before changing the metadata server.

CAUTION

The -R option must not be used on a mounted file system to change the metadata server host without first stopping, disabling, or disconnecting the active metadata server and ensuring that it is restarted before accessing the file system again. Doing so will cause file system corruption.