vos_release - Online in the Cloud

PROGRAM:

NAME

vos_release - Updates read-only volumes to match the read/write source volume

SYNOPSIS

vos release -id <volume name or ID> [-force]
[-cell <cell name>]
[-noauth] [-localauth] [-stayonline]
[-verbose] [-encrypt] [-noresolve] [-help]

vos rel -i <volume name or ID>
[-f] [-c <cell name>] [-stayon]
[-noa] [-l] [-v] [-e] [-nor] [-h]

DESCRIPTION

The vos release command copies the contents of the indicated read/write source volume to
each read-only site defined in the source volume's Volume Location Database (VLDB) entry.
(Use the vos addsite command to define sites as necessary before issuing this command).
Each read-only copy has the same name as read/write source with the addition of a
".readonly" extension.

For users to have a consistent view of the file system, the release of the new volume
version must be atomic: either all read-only sites receive the new version, or all sites
keep the version they currently have. The vos release command is designed to ensure that
all copies of the volume's read-only version match both the read/write source and each
other. In cases where problems such as machine or server process outages prevent
successful completion of the release operation, AFS uses two mechanisms to alert the
administrator.

First, the command interpreter generates an error message on the standard error stream
naming each read-only site that did not receive the new volume version. Second, during the
release operation the Volume Location (VL) Server marks site definitions in the VLDB entry
with flags ("New release" and "Old release") that indicate whether or not the site has the
new volume version. If any flags remain after the operation completes, it was not
successful. The Cache Manager refuses to access a read-only site marked with the "Old
release" flag, which potentially imposes a greater load on the sites marked with the "New
release" flag. It is important to investigate and eliminate the cause of the failure and
then to issue the vos release command as many times as necessary to complete the release
without errors.

The pattern of site flags remaining in the volume's VLDB entry after a failed release
operation can help determine the point at which the operation failed. Use the vos examine
or vos listvldb command to display the VLDB entry. The VL Server sets the flags in concert
with the Volume Server's operations, as follows:

· Before the operation begins, the VL Server sets the "New release" flag on the
read/write site definition in the VLDB entry and the "Old release" flag on read-only
site definitions (unless the read-only site has been defined since the last release
operation and has no actual volume, in which case its site flag remains "Not
released").

· If necessary, the Volume Server creates a temporary copy (a clone) of the read/write
source called the ReleaseClone (see the following discussion of when the Volume Server
does or does not create a new ReleaseClone.) It assigns the ReleaseClone its own
volume ID number, which the VL Server records in the "RClone" field of the source
volume's VLDB entry.

· The Volume Server distributes a copy of the ReleaseClone to each read-only site
defined in the VLDB entry. As the site successfully receives the new clone, the VL
Server sets the site's flag in the VLDB entry to "New release".

· When all the read-only copies are successfully released, the VL Server clears all the
"New release" site flags. The ReleaseClone is no longer needed, so the Volume Server
deletes it and the VL Server erases its ID from the VLDB entry.

By default, the Volume Server determines automatically whether or not it needs to create a
new ReleaseClone:

· If there are no flags ("New release", "Old release", or "Not released") on site
definitions in the VLDB entry, the previous vos release command completed successfully
and all read-only sites currently have the same volume. The Volume Server infers that
the current vos release command was issued because the read/write volume has changed.
The Volume Server creates a new ReleaseClone and distributes it to all of the read-
only sites.

· If any site definition in the VLDB entry is marked with a flag, either the previous
release operation did not complete successfully or a new read-only site was defined
since the last release. The Volume Server does not create a new ReleaseClone, instead
distributing the existing ReleaseClone to sites marked with the "Old release" or "Not
released" flag. As previously noted, the VL Server marks each VLDB site definition
with the "New release" flag as the site receives the ReleaseClone, and clears all
flags after all sites successfully receive it.

To override the default behavior, forcing the Volume Server to create and release a new
ReleaseClone to the read-only sites, include the -force flag. This is appropriate if, for
example, the data at the read/write site has changed since the existing ReleaseClone was
created during the previous release operation.

OPTIONS

-id <volume name or id>
Specifies either the complete name or volume ID number of a read/write volume.

-force
Creates a new ReleaseClone and distributes it all read-only sites regardless of
whether or not any site definitions in the VLDB entry are marked with a flag.

-cell <cell name>
Names the cell in which to run the command. Do not combine this argument with the
-localauth flag. For more details, see vos(1).

-noauth
Assigns the unprivileged identity "anonymous" to the issuer. Do not combine this flag
with the -localauth flag. For more details, see vos(1).

-localauth
Constructs a server ticket using a key from the local /etc/openafs/server/KeyFile
file. The vos command interpreter presents it to the Volume Server and Volume Location
Server during mutual authentication. Do not combine this flag with the -cell argument
or -noauth flag. For more details, see vos(1).

-verbose
Produces on the standard output stream a detailed trace of the command's execution. If
this argument is omitted, only warnings and error messages appear.

-stayonline
Avoids taking replica sites offline by cloning both the source and destinations to
temporary clones, applying updates, and then bringing all clones online as updated
readonly volumes.

-encrypt
Encrypts the command so that the operation's results are not transmitted across the
network in clear text. This option is available in OpenAFS versions 1.4.11 or later
and 1.5.60 or later.

-noresolve
Shows all servers as IP addresses instead of the DNS name. This is very useful when
the server address is registered as 127.0.0.1 or when dealing with multi-homed
servers. This option is available in OpenAFS versions 1.4.8 or later and 1.5.35 or
later.

-help
Prints the online help for this command. All other valid options are ignored.

EXAMPLES

The following command clones the read/write volume usr and releases it to the read-only
sites defined in its VLDB entry.

% vos release usr

PRIVILEGE REQUIRED

The issuer must be listed in the /etc/openafs/server/UserList file on the machine
specified with the -server argument and on each database server machine. If the -localauth
flag is included, the issuer must instead be logged on to a server machine as the local
superuser "root".

Use vos_release online using onworks.net services