[openafs.git] / doc / man-pages / pod8 / bos_salvage.pod

=head1 NAME

bos salvage - Restores internal consistency to a file system or volume

=head1 SYNOPSIS

=for html
<div class="synopsis">

B<bos salvage> S<<< B<-server> <I<machine name>> >>>
    S<<< [B<-partition> <I<salvage partition>>] >>>
    S<<< [B<-volume> <I<salvage volume number or volume name>>] >>>
    S<<< [B<-file> <I<salvage log output file>>] >>> [B<-all>] [B<-showlog>]
    S<<< [B<-parallel> <I<# of max parallel partition salvaging>>] >>>
    S<<< [B<-tmpdir> <I<directory to place tmp files>>] >>>
    S<<< [B<-orphans> (ignore | remove | attach)] >>> S<<< [B<-cell> <I<cell name>>] >>>
    [B<-noauth>] [B<-localauth>] [B<-help>]

B<bos sa> S<<< B<-se> <I<machine name>> >>> S<<< [B<-part> <I<salvage partition>>] >>>
    S<<< [B<-v> <I<salvage volume number or volume name>>] >>>
    S<<< [B<-f> <I<salvage log output file>>] >>> [B<-a>] [B<-sh>]
    [<-para> <I<# of max parallel partition salvaging>>]
    S<<< [B<-t> <I<directory to place tmp files>>] >>>
    S<<< [B<-o> (ignore | remove | attach)] >>> S<<< [B<-c> <I<cell name>>] >>> [B<-n>]
    [B<-l>] [B<-h>]

=for html
</div>

=head1 DESCRIPTION

The B<bos salvage> command salvages (restores internal consistency to) one
or more volumes on the file server machine named by the B<-server>
argument. When processing one or more partitions, the command restores
consistency to corrupted read/write volumes where possible. For read-only
or backup volumes, it inspects only the volume header:

=over 4

=item *

If the volume header is corrupted, the Salvager removes the volume
completely and records the removal in its log file,
F</usr/afs/logs/SalvageLog>. Issue the B<vos release> or B<vos backup>
command to create the read-only or backup volume again.

=item *

If the volume header is intact, the Salvager skips the volume (does not
check for corruption in the contents). However, if the File Server notices
corruption as it initializes, it sometimes refuses to attach the volume or
bring it online. In this case, it is simplest to remove the volume by
issuing the B<vos remove> or B<vos zap> command. Then issue the B<vos
release> or B<vos backup> command to create it again.

=back

Use the indicated arguments to salvage a specific number of volumes:

=over 4

=item *

To process all volumes on a file server machine, provide the B<-server>
argument and the B<-all> flag. No volumes on the machine are accessible to
Cache Managers during the salvage operation, because the BOS Server stops
the File Server and Volume Server processes while the Salvager runs. The
BOS Server automatically restarts them when the operation completes.

=item *

To process all volumes on one partition, provide the B<-server> and
B<-partition> arguments. As for a salvage of the entire machine, no
volumes on the machine are accessible to Cache Managers during the salvage
operation. The BOS Server automatically restarts the File Server and
Volume Server when the operation completes.

=item *

To salvage only one read/write volume, combine the B<-server>,
B<-partition>, and B<-volume> arguments. Only that volume is inaccessible
to Cache Managers, because the BOS Server does not shutdown the File
Server and Volume Server processes during the salvage of a single
volume. Do not name a read-only or backup volume with the B<-volume>
argument. Instead, remove the volume, using the B<vos remove> or B<vos
zap> command. Then create a new copy of the volume with the B<vos release>
or B<vos backup> command.

=back

During the salvage of an entire machine or partition, the B<bos status>
command reports the C<fs> process's auxiliary status as C<Salvaging file
system>.

The Salvager always writes a trace to the F</usr/afs/logs/SalvageLog> file
on the file server machine where it runs. To record the trace in another
file as well (either in AFS or on the local disk of the machine where the
B<bos salvage> command is issued), name the file with the B<-file>
argument. To display the trace on the standard output stream as it is
written to the F</usr/afs/logs/SalvageLog> file, include the B<-showlog>
flag.

By default, multiple Salvager subprocesses run in parallel: one for each
partition up to four, and four subprocesses for four or more
partitions. To increase or decrease the number of subprocesses running in
parallel, provide a positive integer value for the B<-parallel> argument.

If there is more than one server partition on a physical disk, the
Salvager by default salvages them serially to avoid the inefficiency of
constantly moving the disk head from one partition to another. However,
this strategy is often not ideal if the partitions are configured as
logical volumes that span multiple disks. To force the Salvager to salvage
logical volumes in parallel, provide the string C<all> as the value for
the B<-parallel> argument. Provide a positive integer to specify the
number of subprocesses to run in parallel (for example, C<-parallel 5all>
for five subprocesses), or omit the integer to run up to four
subprocesses, depending on the number of logical volumes being salvaged.

The Salvager creates temporary files as it runs, by default writing them
to the partition it is salvaging. The number of files can be quite large,
and if the partition is too full to accommodate them, the Salvager
terminates without completing the salvage operation (it always removes the
temporary files before exiting). Other Salvager subprocesses running at
the same time continue until they finish salvaging all other partitions
where there is enough disk space for temporary files. To complete the
interrupted salvage, reissue the command against the appropriate
partitions, adding the B<-tmpdir> argument to redirect the temporary files
to a local disk directory that has enough space.

The B<-orphans> argument controls how the Salvager handles orphaned files
and directories that it finds on server partitions it is salvaging. An
I<orphaned> element is completely inaccessible because it is not
referenced by the vnode of any directory that can act as its parent (is
higher in the filespace). Orphaned objects occupy space on the server
partition, but do not count against the volume's quota.

=head1 CAUTIONS

Running this command can result in data loss if the Salvager process can
repair corruption only by removing the offending data. Consult the I<IBM
AFS Administration Guide> for more information.

=head1 OPTIONS

=over 4

=item B<-server> <I<machine name>>

Indicates the file server machine on which to salvage volumes.  Identify
the machine by IP address or its host name (either fully-qualified or
abbreviated unambiguously). For details, see L<bos(8)>.

=item B<-partition> <I<salvage partition>>

Specifies a single partition on which to salvage all volumes.  Provide the
complete partition name (for example F</vicepa>) or one of the following
abbreviated forms:

   /vicepa     =     vicepa      =      a      =      0
   /vicepb     =     vicepb      =      b      =      1

After F</vicepz> (for which the index is 25) comes

   /vicepaa    =     vicepaa     =      aa     =      26
   /vicepab    =     vicepab     =      ab     =      27

and so on through

   /vicepiv    =     vicepiv     =      iv     =      255

=item B<-volume> <I<salvage volume id or name>>

Specifies the name or volume ID number of a read/write volume to
salvage. The B<-partition> argument must be provided along with this one.

=item B<-file> <I<salvage log output file>>

Specifies the complete pathname of a file into which to write a trace of
the salvage operation, in addition to the F</usr/afs/logs/SalvageLog> file
on the server machine. If the file pathname is local, the trace is written
to the specified file on the local disk of the machine where the B<bos
salvage> command is issued. If the B<-volume> argument is included, the
file can be in AFS, though not in the volume being salvaged. Do not
combine this argument with the B<-showlog> flag.

=item B<-all>

Salvages all volumes on all of the partitions on the machine named by the
B<-server> argument.

=item B<-showlog>

Displays the trace of the salvage operation on the standard output stream,
as well as writing it to the F</usr/afs/logs/SalvageLog> file.  Do not
combine this flag with the B<-file> argument.

=item B<-parallel> <I<# of max parallel partition salvaging>>

Specifies the maximum number of Salvager subprocesses to run in
parallel. Provide one of three values:

=over 4

=item *

An integer from the range C<1> to C<32>. A value of C<1> means that a
single Salvager process salvages the partitions sequentially.

=item *

The string C<all> to run up to four Salvager subprocesses in parallel on
partitions formatted as logical volumes that span multiple physical
disks. Use this value only with such logical volumes.

=item *

The string all followed immediately (with no intervening space) by an
integer from the range C<1> to C<32>, to run the specified number of
Salvager subprocesses in parallel on partitions formatted as logical
volumes. Use this value only with such logical volumes.

=back

The BOS Server never starts more Salvager subprocesses than there are
partitions, and always starts only one process to salvage a single
volume. If this argument is omitted, up to four Salvager subprocesses run
in parallel.

=item B<-tmpdir> <I<directory to place tmp files>>

Specifies the full pathname of a local disk directory to which the
Salvager process writes temporary files as it runs. If this argument is
omitted, or specifies an ineligible or nonexistent directory, the Salvager
process writes the files to the partition it is currently salvaging.

=item B<-orphans> (ignore | remove | attach)

Controls how the Salvager handles orphaned files and directories.  Choose
one of the following three values:

=over 4

=item ignore

Leaves the orphaned objects on the disk, but prints a message to the
F</usr/afs/logs/SalvageLog> file reporting how many orphans were found and
the approximate number of kilobytes they are consuming. This is the
default if the B<-orphans> argument is omitted.

=item remove

Removes the orphaned objects, and prints a message to the
F</usr/afs/logs/SalvageLog> file reporting how many orphans were removed
and the approximate number of kilobytes they were consuming.

=item attach

Attaches the orphaned objects by creating a reference to them in the vnode
of the volume's root directory. Since each object's actual name is now
lost, the Salvager assigns each one a name of the following form:

=over 4

=item *

C<__ORPHANFILE__.I<index>> for files.

=item *

C<__ORPHANDIR__.I<index>> for directories.

=back

where I<index> is a two-digit number that uniquely identifies each
object. The orphans are charged against the volume's quota and appear in
the output of the B<ls> command issued against the volume's root
directory.

=back

=item B<-cell> <I<cell name>>

Names the cell in which to run the command. Do not combine this argument
with the B<-localauth> flag. For more details, see L<bos(8)>.

=item B<-noauth>

Assigns the unprivileged identity C<anonymous> to the issuer. Do not
combine this flag with the B<-localauth> flag. For more details, see
L<bos(8)>.

=item B<-localauth>

Constructs a server ticket using a key from the local
F</usr/afs/etc/KeyFile> file. The B<bos> command interpreter presents the
ticket to the BOS Server during mutual authentication. Do not combine this
flag with the B<-cell> or B<-noauth> options. For more details, see
L<bos(8)>.

=item B<-help>

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

=back

=head1 EXAMPLES

The following command salvages all volumes on the F</vicepd> partition of
the machine C<db3.abc.com>:

   % bos salvage -server db3.abc.com -partition /vicepd

The following command salvages the volume with volume ID number 536870988
on partition F</vicepb> of the machine C<fs2.abc.com>:

   % bos salvage -server fs2.abc.com -partition /vicepb -volume 536870988

The following command salvages all volumes on the machine
C<fs4.abc.com>. Six Salvager processes run in parallel rather than the
default four.

   % bos salvage -server fs4.abc.com -all -parallel 6

=head1 PRIVILEGE REQUIRED

The issuer must be listed in the F</usr/afs/etc/UserList> file on the
machine named by the B<-server> argument, or must be logged onto a server
machine as the local superuser C<root> if the B<-localauth> flag is
included.

=head1 SEE ALSO

L<KeyFile(5)>,
L<SalvageLog(5)>,
L<UserList(5)>,
L<bos(8)>,
L<salvager(8)>,
L<vos_backup(1)>,
L<vos_release(1)>,
L<vos_remove(1)>,
L<vos_zap(1)>

I<IBM AFS Administration Guide>

=head1 COPYRIGHT

IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.

This documentation is covered by the IBM Public License Version 1.0.  It was
converted from HTML to POD by software written by Chas Williams and Russ
Allbery, based on work by Alf Wachsmann and Elizabeth Cassell.