[hcoop/debian/openafs.git] / doc / man-pages / pod8 / fragments / salvager-description.pod

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:

=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

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 F</usr/afs/local/BosConfig> file
with the B<bos create> command. It is also possible to invoke the Salvager
remotely by issuing the B<bos salvage> command.

Combine the command's options as indicated to salvage different numbers of
read/write volumes:

=over 4

=item *

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.

=item *

To salvage all of the volumes on one partition, provide the B<-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.

=item *

To salvage only one volume, combine the B<-partition> and B<-volumeid>
arguments. Only that volume is inaccessible to Cache Managers, because the
BOS Server does not shutdown the File Server and Volume Server processes.

=back

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 B<-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
B<-nowrite> argument to bringing undamaged volumes online without
attempting to salvage damaged volumes. Then use the B<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 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 as if they were on separate disks, provide the
string C<all> as the value for the B<-parallel> argument.

To set both parameters at the same time, append the number of Salvager
processes to the string C<all>. For example, C<-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 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.

To generate a list of all mount points that reside in one or more volumes,
rather than actually salvaging them, include the B<-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.
Commit	Line	Data
805e021f CE	1	The Salvager restores internal consistency to corrupted read/write volumes
	2	on the local file server machine where possible. For read-only or backup
	3	volumes, it inspects only the volume header:
	4
	5	=over 4
	6
	7	=item *
	8
	9	If the volume header is corrupted, the Salvager removes the volume
	10	completely and records the removal in its log file,
	11	F</usr/afs/logs/SalvageLog>. Issue the B<vos release> or B<vos backup>
	12	command to create the read-only or backup volume again.
	13
	14	=item *
	15
	16	If the volume header is intact, the Salvager skips the volume (does not
	17	check for corruption in the contents). However, if the File Server notices
	18	corruption as it initializes, it sometimes refuses to attach the volume or
	19	bring it online. In this case, it is simplest to remove the volume by
	20	issuing the B<vos remove> or B<vos zap> command. Then issue the B<vos
	21	release> or B<vos backup> command to create it again.
	22
	23	=back
	24
	25	Unlike other server process initialization commands, the Salvager
	26	command is designed to be issued at the command shell prompt, as well as
	27	being placed into a file server machine's F</usr/afs/local/BosConfig> file
	28	with the B<bos create> command. It is also possible to invoke the Salvager
	29	remotely by issuing the B<bos salvage> command.
	30
	31	Combine the command's options as indicated to salvage different numbers of
	32	read/write volumes:
	33
	34	=over 4
	35
	36	=item *
	37
	38	To salvage all volumes on the file server machine, provide no arguments.
	39	No volumes on the machine are accessible to Cache Managers during the
	40	salvage, because the BOS Server stops the File Server and Volume Server
	41	processes while the Salvager runs.
	42
	43	=item *
	44
	45	To salvage all of the volumes on one partition, provide the B<-partition>
	46	argument. As for a salvage of all volumes on the machine, no volumes on
	47	the machine are accessible to Cache Managers during the salvage operation.
	48
	49	=item *
	50
	51	To salvage only one volume, combine the B<-partition> and B<-volumeid>
	52	arguments. Only that volume is inaccessible to Cache Managers, because the
	53	BOS Server does not shutdown the File Server and Volume Server processes.
	54
	55	=back
	56
	57	The Salvager normally salvages only those read/write volumes that are
	58	marked as having been active when a crash occurred. To have it salvage all
	59	relevant read/write volumes, add the B<-force> flag.
	60
	61	The Salvager normally creates new inodes as it repairs damage. If the
	62	partition is so full that there is no room for new inodes, use the
	63	B<-nowrite> argument to bringing undamaged volumes online without
	64	attempting to salvage damaged volumes. Then use the B<vos move> command to
65	move one or more of the undamaged volumes to other partitions, freeing up
66	the space that the Salvager needs to create new inodes.
67
68	By default, multiple Salvager subprocesses run in parallel: one for each
69	partition up to four, and four subprocesses for four or more
70	partitions. To increase or decrease the number of subprocesses running in
71	parallel, provide a positive integer value for the B<-parallel> argument.
72
73	If there is more than one server partition on a physical disk, the
74	Salvager by default salvages them serially to avoid the inefficiency of
75	constantly moving the disk head from one partition to another. However,
76	this strategy is often not ideal if the partitions are configured as
77	logical volumes that span multiple disks. To force the Salvager to salvage
78	logical volumes in parallel as if they were on separate disks, provide the
79	string C<all> as the value for the B<-parallel> argument.
80
81	To set both parameters at the same time, append the number of Salvager
82	processes to the string C<all>. For example, C<-parallel all5> treats
83	each partition as a separate disk and runs five Salvager processes, thus
84	salvaging five partitions at a time.
85
86	The Salvager creates temporary files as it runs, by default writing them
87	to the partition it is salvaging. The number of files can be quite large,
88	and if the partition is too full to accommodate them, the Salvager
89	terminates without completing the salvage operation (it always removes the
90	temporary files before exiting). Other Salvager subprocesses running at
91	the same time continue until they finish salvaging all other partitions
92	where there is enough disk space for temporary files. To complete the
93	interrupted salvage, reissue the command against the appropriate
94	partitions, adding the B<-tmpdir> argument to redirect the temporary files
95	to a local disk directory that has enough space.
96
97	The B<-orphans> argument controls how the Salvager handles orphaned files
98	and directories that it finds on server partitions it is salvaging. An
99	I<orphaned> element is completely inaccessible because it is not
100	referenced by the vnode of any directory that can act as its parent (is
101	higher in the filespace). Orphaned objects occupy space on the server
102	partition, but do not count against the volume's quota.
103
104	To generate a list of all mount points that reside in one or more volumes,
105	rather than actually salvaging them, include the B<-showmounts> flag.
106
107	This command does not use the syntax conventions of the AFS command
108	suites. Provide the command name and all option names in full.
109