thin_check(8) System Manager's Manual thin_check(8)
NAME
thin_check - validates thin provisioning metadata on a device or file
SYNOPSIS
thin_check [options] {device|file}
DESCRIPTION
thin_check checks thin provisioning metadata created by the device-map-
per thin provisioning target on a device or file.
The tool cannot be run on live metadata unless the --metadata-snapshot
option is used.
OPTIONS
-q, --quiet
Suppress output messages, return only exit code.
-h, --help
Print help and exit.
-V, --version
Output version information and exit.
--super-block-only
Only check the superblock.
--skip-mappings
Skip checking of the block mappings which make up the bulk of
the metadata.
--ignore-non-fatal-errors
Will only return a non-zero exit code if it finds a fatal error.
An example of a nonfatal error is an incorrect data block reference count
causing a block to be considered allocated when it in fact isn't. Ignoring
errors for a long time is not advised, you really should be using
thin_repair to fix them.
--clear-needs-check-flag
Clears the 'needs_check' flag in the superblock.
The kernel may set a flag to force the pool to be checked before it's next
activated. Set this switch to clear the flag if the check is successful.
If the metadata check failed, the flag is not cleared and a thin_repair run
is needed to fix any issues. After thin_repair succeeded, you may run
thin_check again.
--metadata-snapshot, -m
Check the metadata snapshot.
This will check the devices tree and mappings in a metadata snapshot.
The snap does not contain space maps, so these will not be checked. This
may be used on live metadata.
--auto-repair
Automatically repair any trivial issues found with the metadata.
Currently only fixes metadata leaks.
--override-mapping-root <block>
Specify a mapping root to use.
Don't use this. This overrides what's specified in the superblock. Only
use this if you really understand the metadata format and are trying to
recover damaged metadata.
EXAMPLE
Analyses thin provisioning metadata on logical volume /dev/vg/metadata:
$ thin_check /dev/vg/metadata
The device must not be actively used by the target when running.
DIAGNOSTICS
thin_check returns an exit code of 0 for success or 1 for error.
SEE ALSO
thin_dump(8), thin_repair(8), thin_restore(8), thin_rmap(8), thin_meta-
data_size(8)
AUTHOR
Joe Thornber <ejt@redhat.com>, Heinz Mauelshagen <heinzm@redhat.com>
System Manager's Manual Device Mapper Tools thin_check(8)
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