lustre_rsync(8)

NAME

lustre_rsync - Utility to replicate a Lustre Filesystem

SYNOPSIS

DESCRIPTION

lustre_rsync is designed to replicate a Lustre filesystem (source filesystem) to another target filesystem (any filesystem type) efficiently by using Lustre MDT changelogs. A changelog user must be registered (see lctl (8) changelog_register) before using this tool.

The source and the target filesystems must be identical before the changelog user is registered. If the filesystems are discrepant, a utility like rsync may be used to make them identical.

OPTIONS

-s, --source=SRC

The path to the root of the Lustre filesystem which will be replicated. Mandatory if a valid statuslog created during an previous replication operation (--statuslog) is not specified.

-t, --target=TGT

The path to the root where the filesystem we be replicated. Mandatory if a valid statuslog created during an previous replication operation (--statuslog) is not specified. This option can be repeated if multiple replication targets are desired.

-m, --mdt=MDT

The metadata device which is to be replicated. A changelog user must be registered for this device. Mandatory if a valid statuslog created during an previous replication operation (--statuslog) is not specified.

-u, --user=USER_ID

The changelog user id for the above MDT device. See lctl(8) changelog_register. Mandatory if a valid statuslog created during an previous replication operation (--statuslog) is not specified.

-l, --statuslog=LOG

A status log file to which the status of replication is saved. When lustre_rsync is started, the state from a previous replication will be read from here.

If a statuslog from a previous replication operation is specified, the otherwise mandatory options like --source, --target and --mdt may be skipped.

By specifying the options like --source, --target and --mdt in addition to the --statuslog option, the parameters in the statuslog can be overridden. The command line options take precedence over the ones from the statuslog.

-x, --xattr {yes|no}

Specify whether extended attributes are replicated or not. The default is to replicate extended attributes. Disabling xattrs will mean that Lustre striping information will not be replicated.

-v, --verbose

Produce a verbose output.

--dry-run

Shows what the program would do without actually replicating data.

--abort-on-err

Stop processing upon first error. Default is to continue processing.

EXAMPLES

Register a changelog consumer for MDT lustre-MDT0000:

# ssh $MDS lctl changelog_register --device lustre-MDT0000 -n
cl1

Replicate the lustre filesystem /mnt/lustre to /mnt/target:

# lustre_rsync --source=/mnt/lustre --target=/mnt/target --mdt=lustre-MDT0000 --user=cl1 --statuslog replicate.log --verbose
Lustre filesystem: lustre
MDT device: lustre-MDT0000
Source: /mnt/lustre
Target: /mnt/target
Statuslog: replicate.log
Changelog registration: cl1
Starting changelog record: 0
Errors: 0
lustre_rsync took 1 seconds
Changelog records consumed: 22

After the filesystem undergoes some changes, replicate the changes. Only the statuslog needs to be specified as it has all the parameters passed earlier:

# lustre_rsync --statuslog replicate.log --verbose
Replicating Lustre filesystem: lustre
MDT device: lustre-MDT0000
Source: /mnt/lustre
Target: /mnt/target
Statuslog: replicate.log
Changelog registration: cl1
Starting changelog record: 22
Errors: 0
lustre_rsync took 2 seconds
Changelog records consumed: 42

To replicate the lustre filesystem /mnt/lustre to /mnt/target1 and /mnt/target2:

# lustre_rsync --source=/mnt/lustre --target=/mnt/target1 --target=/mnt/target2 --mdt=lustre-MDT0000 --user=cl1 --statuslog replicate.log

AVAILABILITY

The lustre_rsync command is part of the lustre(7) filesystem package since release 1.7.0

SEE ALSO

lfs(1), lustre(7), lctl(8)