salvager - Initializes the Salvager component of the fs
process
salvager
[initcmd]
[-partition <name of partition to salvage>]
[-volumeid <volume id to salvage>]
[-debug] [-nowrite]
[-inodes] [-force] [-oktozap] [-rootinodes]
[-salvagedirs] [-blockreads]
[-parallel <# of max parallel partition salvaging>]
[-tmpdir <name of dir to place tmp files>]
[-showlog] [-showsuid] [-showmounts]
[-orphans (ignore | remove | attach)]
[-help]
The salvager command initializes the Salvager component of
the "fs" 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 bos create command. It is also possible to invoke the
Salvager remotely by issuing the bos salvage command.
Combine the command's options as indicated to salvage different
numbers of read/write volumes:
- 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 flag.
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
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 as if they were on separate disks, provide the string
"all" as the value for the
-parallel argument.
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 argument to redirect the temporary
files to a local disk directory that has enough space.
The -orphans argument controls how the Salvager handles
orphaned files and directories that it finds on server partitions it is
salvaging. An 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.
To generate a list of all mount points that reside in one or more
volumes, rather than actually salvaging them, include the -showmounts
flag.
This command does not use the syntax conventions of the AFS
command suites. Provide the command name and all option names in full.
- [initcmd]
- Accommodates the command's use of the AFS command parser, and is
optional.
- -partition
<name of partition to salvage>
- Specifies the name of the partition to salvage. Specify the full partition
name using the form /vicepx or
/vicepxx. 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.
- -debug
- 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 interpret.
- -nowrite
- Brings all undamaged volumes online without attempting to salvage any
damaged volumes.
- -inodes
- Records in the /var/log/openafs/SalvageLog file a list of all AFS
inodes that the Salvager modified.
- -force
- Inspects all volumes for corruption, not just those that are marked as
having been active when a crash occurred.
- -oktozap
- 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.
- -rootinodes
- Records in the /var/log/openafs/SalvageLog file a list of all AFS
inodes owned by the local superuser
"root".
- -salvagedirs
- 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.
- -blockreads
- 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 salvaging>
- 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 volumes.
- 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
volumes.
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 files>
- 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.
- -showlog
- Displays on the standard output stream all log data that is being written
to the /var/log/openafs/SalvageLog file.
- -showsuid
- Displays a list of the pathnames for all files that have the setuid or
setgid mode bit set.
- -showmounts
- 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:
- ignore
- 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 omitted.
- remove
- 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.
- 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:
- "__ORPHANFILE__.index" for files.
- "__ORPHANDIR__.index" for directories.
where 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 ls command issued against the volume's root
directory.
- -help
- 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/salvager -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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