dasalvager - Initializes the Salvager component of the dafs process
<name of partition to salvage
<volume id to salvage
<# of max parallel partition salvaging
<name of dir to place tmp files
(ignore | remove | attach)]
command initializes the Salvager component of the
"dafs" process. In the conventional configuration, its binary file
is located in the /usr/lib/openafs
directory on a file server machine.
The Salvager restores internal consistency to corrupted read/write volumes on
the local file server machine where possible. For read-only or backup volumes,
it inspects only the volume header:
- If the volume header is corrupted, the Salvager removes the
volume completely and records the removal in its log file,
/var/log/openafs/SalvageLog. Issue the vos release or vos
backup command to create the read-only or backup volume again.
- 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 vos remove or vos zap
command. Then issue the vos release or vos backup
command to create it again.
Unlike other server process initialization commands, the Salvager command is
designed to be issued at the command shell prompt, as well as being placed
into a file server machine's /etc/openafs/BosConfig
file with the
command. It is also possible to invoke the Salvager remotely
by issuing the bos salvage
Combine the command's options as indicated to salvage different numbers of
- To salvage all volumes on the file server machine, provide
no arguments. No volumes on the machine are accessible to Cache Managers
during the salvage, because the BOS Server stops the File Server and
Volume Server processes while the Salvager runs.
- To salvage all of the volumes on one partition, provide the
-partition argument. As for a salvage of all volumes on the
machine, no volumes on the machine are accessible to Cache Managers during
the salvage operation.
- To salvage only one volume, combine the -partition
and -volumeid arguments. Only that volume is inaccessible to Cache
Managers, because the BOS Server does not shutdown the File Server and
Volume Server processes.
The Salvager normally salvages only those read/write volumes that are marked as
having been active when a crash occurred. To have it salvage all relevant
read/write volumes, add the -force
The Salvager normally creates new inodes as it repairs damage. If the partition
is so full that there is no room for new inodes, use the -nowrite
argument to bringing undamaged volumes online without attempting to salvage
damaged volumes. Then use the vos move
command to move one or more of
the undamaged volumes to other partitions, freeing up the space that the
Salvager needs to create new inodes.
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 -parallel
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
as if they were on separate disks, provide the string "all" as the
value for the -parallel
To set both parameters at the same time, append the number of Salvager processes
to the string "all". For example, "-parallel all5" treats
each partition as a separate disk and runs five Salvager processes, thus
salvaging five partitions at a time.
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 -tmpdir
redirect the temporary files to a local disk directory that has enough space.
argument controls how the Salvager handles orphaned files
and directories that it finds on server partitions it is salvaging. An
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.
To generate a list of all mount points that reside in one or more volumes,
rather than actually salvaging them, include the -showmounts
This command does not use the syntax conventions of the AFS command suites.
Provide the command name and all option names in full.
- Accommodates the command's use of the AFS command parser,
and is optional.
- -partition <name of partition to
- Specifies the name of the partition to salvage. Specify the
full partition name using the form /vicepx or
/vicep xx. Omit this argument to salvage every
partition on the file server machine.
- -volumeid <volume id to salvage>
- Specifies the volume ID of a specific read/write volume to
salvage. The -partition argument must be provided along with this
one and specify the volume's actual site.
- Allows only one Salvager subprocess to run at a time,
regardless of the setting of the -parallel option. Include it when
running the Salvager in a debugger to make the trace easier to
- Brings all undamaged volumes online without attempting to
salvage any damaged volumes.
- Records in the /var/log/openafs/SalvageLog file a
list of all AFS inodes that the Salvager modified.
- Inspects all volumes for corruption, not just those that
are marked as having been active when a crash occurred.
- Removes a volume that is so damaged that even issuing the
vos zap command with the -force flag is ineffective. Combine
it with the -partition and -volumeid arguments to identify
the volume to remove. Using this flag will destroy data that cannot be
read, so use only with caution and when you're certain that nothing in
that volume is still needed.
- Records in the /var/log/openafs/SalvageLog file a
list of all AFS inodes owned by the local superuser "root".
- Salvages entire directory structures, even if they do not
appear to be damaged. By default, the Salvager salvages a directory only
if it is flagged as corrupted.
- Forces the Salvager to read a partition one disk block (512
bytes) at a time and to skip any blocks that are too badly damaged to be
salvaged. This allows it to salvage as many volumes as possible. By
default, the Salvager reads large disk blocks, which can cause it to exit
prematurely if it encounters disk errors. Use this flag if the partition
to be salvaged has disk errors.
- -parallel <# of max parallel partition
- Specifies the maximum number of Salvager subprocesses to
run in parallel. Provide one of three values:
- An integer from the range 1 to 32. A value of 1 means that
a single Salvager process salvages the partitions sequentially.
- The string "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
- The string "all" followed immediately (with no
intervening space) by an integer from the range 1 to 32, to run the
specified number of Salvager subprocesses in parallel on partitions
formatted as logical volumes. Use this value only with such logical
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 but
partitions on the same device are salvaged serially.
- -tmpdir <name of dir to place tmp
- Names a local disk directory in which the Salvager places
the temporary files it creates during a salvage operation, instead of
writing them to the partition being salvaged (the default). If the
Salvager cannot write to the specified directory, it attempts to write to
the partition being salvaged.
- Displays on the standard output stream all log data that is
being written to the /var/log/openafs/SalvageLog file.
- Displays a list of the pathnames for all files that have
the setuid or setgid mode bit set.
- Records in the /var/log/openafs/SalvageLog file all
mount points found in each volume. The Salvager does not repair corruption
in the volumes, if any exists.
- -orphans (ignore | remove | attach)
- Controls how the Salvager handles orphaned files and
directories. Choose one of the following three values:
- Leaves the orphaned objects on the disk, but prints a
message to the /var/log/openafs/SalvageLog file reporting how many
orphans were found and the approximate number of kilobytes they are
consuming. This is the default if the -orphans argument is
- Removes the orphaned objects, and prints a message to the
/var/log/openafs/SalvageLog file reporting how many orphans were
removed and the approximate number of kilobytes they were consuming.
- 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
- "__ORPHANFILE__.index" for files.
- "__ORPHANDIR__.index" for
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
command issued against the volume's root directory.
- Prints the online help for this command. All other valid
options are ignored.
The following command instructs the Salvager to attempt to salvage the volume
with volume ID 258347486 on /vicepg
on the local machine.
% /usr/lib/openafs/dasalvager -partition /vicepg -volumeid 258347486
To issue the command at the shell prompt, the issuer must be logged in as the
local superuser "root".
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