thin_migrate.8

thin_migrate

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
EXAMPLE
DIAGNOSTICS
AUTHOR

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NAME

thin_migrate

SYNOPSIS

thin_migrate [options] —source-dev {device} —dest-dev {device} **
thin_migrate** [options] —source-dev {device} —dest-file {file}

DESCRIPTION

thin_migrate copies provisioned data blocks from a thin device to another device or file. It is designed for cloning a read-only snapshot or thin volume within a live thin-pool. A metadata snapshot is required to read the data mappings.

OPTIONS

-h, —help

Print help and exit.

-V, —version

Print version information and exit.

—source-dev {device}

The input read-only thin device to copy.

—dest-dev {device}

The output device as the copy destination.

—dest-file {file}

The output file as the copy destination.

-q, —quit

Suppress output messages, return only exit code.

—buffer-size-meg {size}

Specify the size of the data buffers, in megabytes.

EXAMPLE

Assuming that there’s a thin snapshot ’vg/snap’ to copy, we must first set the snapshot to read-only:

$ lvchange vg/snap —permission r

Next, create a metadata snapshot for running thin_migrate:

$ dmsetup message vg-mythinpool-tpool 0 reserve_metadata_snap

Once the metadata snapshot is created, copy the snapshot into another linear or thin volume. The destination volume must have the same size as the source device.

$ thin_migrate —src-device /dev/vg/snap —dest-device /dev/vg2/dest

Alternatively, copy the snapshot into a file. thin_migrate can optionally create the destination file if it is not present, or the size of the file will be truncated to match that of the source device.

$ thin_migrate —src-device /dev/vg/snap —dest-file dest.bin

Finally, release the metadata snapshot after thin_migrate finishes its job:

$ dmsetup message vg-mythinpool-tpool 0 release_metadata_snap

DIAGNOSTICS

thin_migrate returns an exit code of 0 for success or 1 for error.

AUTHOR

Joe Thornber <ejt@redhat.com>

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