Ubuntu Manpage: fpsync — Synchronize directories in parallel using fpart and an external tool

NAME

       fpsync — Synchronize directories in parallel using fpart and an external tool

SYNOPSIS

       fpsync  [-p]  [-n  jobs]  [-w  wrks]  [-m  tool]  [-T  path]  [-f  files]  [-s  size]  [-E] [-o toolopts]
              [-O fpartopts] [-S] [-t tmpdir] [-d shdir] [-M mailaddr] [-v] src_dir/ dst_url/
       fpsync -l
       fpsync -r runid [-R] [OPTIONS...]
       fpsync -a runid
       fpsync -D runid

DESCRIPTION

       The fpsync tool synchronizes directories in parallel using fpart(1) and rsync(1), cpio(1) or tar(1).   It
       computes subsets of src_dir/ and spawns jobs to synchronize them to dst_url/.

       Synchronization  jobs  can  be executed either locally or remotely (using SSH workers, see option -w) and
       are executed on-the-fly while filesystem crawling goes on.  This makes fpsync a good tool  for  migrating
       large filesystems.

COMMON OPTIONS

       -t tmpdir
               Set  fpsync  temporary directory to tmpdir.  This directory remains local and does not need to be
               shared amongst SSH workers when using the -w option.  Default: /tmp/fpsync

       -d shdir
               Set fpsync shared directory to shdir.  This option is mandatory when using SSH workers and set by
               default to tmpdir when running locally.  The specified directory must be an absolute  path  ;  it
               will be used to handle communications with SSH hosts (sharing partitions and log files) and, as a
               consequence,  must  be  made available to all participating hosts (e.g. through a r/w NFS mount),
               including the master one running fpsync.

       -M mailaddr
               Send an e-mail to mailaddr after a run.  Multiple -space-separated- addresses can  be  specified.
               That option requires the mail(1) client to be installed and configured on the master host running
               fpsync.

       -v      Verbose mode.  Can be be specified several times to increase verbosity level.

       -h      Print help

SYNCHRONIZATION OPTIONS

-m tool
External copy tool used to synchronize files. Currently supported tools are: rsync, cpio, tar,
and tarify. Default: rsync. When using cpio or tar and more than one worker, directory
timestamps may not be replicated. A second pass will fix them. Special tool tarify generates
tarballs into destination directory.

-T path
Specify absolute path of copy tool (guessed by default). If you force a specific path, the copy
tool must be present at that path on each worker. That path cannot be changed when resuming a
run.

-f files
Transfer at most files files or directories per sync job. 0 means unlimited but you must at
least specify one file or size limit. Default: 2000

-s size
Transfer at most size bytes per sync job. 0 means unlimited but you must at least specify one
file or size limit. You can use a human-friendly unit suffix here (k, m, g, t, p).
Default: 4294967296 (4 GB)

-E Work on a per-directory basis (rsync tool only). In that mode, fpsync works with lists of
directories instead of files. That mode may generate coarse-grained lists but enables rsync(1)
's --delete option by default ( WARNING!!! ), making it a good candidate for a final (cleaning)
pass after several incremental passes using standard (file) mode. When option -E is specified
twice, it enables 'aggressive' mode which isolates erroneous directories and enables recursive
synchronization for them. This advanced mode can be useful to try to overcome transcient errors
such as Linux SMB client deferring opendir() calls to support compound SMB requests.

-o toolopts
Override default rsync(1), cpio(1) or tar(1) options with toolopts. Use this option with care as
certain options are incompatible with a parallel usage (e.g. rsync's --delete). Default for
rsync: “-lptgoD -v --numeric-ids”. Empty for cpio, tar and tarify.

-O fpartopts
Override default fpart(1) options with fpartopts. Options and values must be separated by a pipe
character.
Default: “-x|.zfs|-x|.snapshot*|-x|.ckpt”.

-S Sudo mode. Use sudo(8) for filesystem crawling and synchronizations.

src_dir/
Source directory. It must be absolute and available on all participating hosts (including the
master one, running fpsync).

dst_url/
Destination directory or URL (rsync tool only). If a remote URL is provided, it must be
supported by rsync(1). All participating workers must be able to reach that target.

JOB HANDLING AND DISPATCHING OPTIONS

       -n jobs
               Start jobs concurrent sync jobs (either locally or remotely, see below) per run.  Default: 2

       -w wrks
               Use  remote  SSH  wrks to synchronize files.  Synchronization jobs are executed locally when this
               option is not set.  wrks is a space-separated list of login@machine connection strings and can be
               specified several times.  You must be allowed to connect to those machines using  a  SSH  key  to
               avoid user interaction.

RUN HANDLING OPTIONS

-p Prepare mode: prepare, test synchronization environment, start fpart(1) and create partitions but
do not actually start transfers. That mode can be used to create a run that can then be resumed
using option -r.

-l List previous runs and their status.

-r runid
Resume run runid and restart synchronizing remaining partitions from a previous run. runid is
displayed when using verbose mode (see option -v) or prepare mode (option -p) and can be
retrieved afterwards using option -l. Note that filesystem crawling is skipped when resuming a
previous run. As a consequence, options -m, -f, -s, -E, -o, -O, -S, src_dir/, and dst_url/ are
ignored.

-R Replay mode: when using option -r, force re-synchronizing run's all partitions instead of
remaining ones only. That mode can be useful to skip filesystem crawling when you have to replay
a final pass several times and you know directory structure has not changed in the meantime (you
may miss files if you use replay mode with a standard, file-based, run).

-a runid
Archive run runid (including partition files, logs, queue and work directories) to tmpdir. That
option requires the tar(1) client to be installed on the master host running fpsync.

-D runid
Delete run runid (including partition files, logs, queue and work directories).

RUNNING FPSYNC

Each fpsync run generates a unique runid, which is displayed in verbose mode (see option -v) and within
log files. You can use that runid to resume a previous run (see option -r). fpsync will then restart
synchronizing data from the parts that were being synchronized at the time it stopped.

This unique feature gives the administrator the ability to stop fpsync and restart it later, without
having to restart the whole filesystem crawling and synchronization process. Note that resuming is only
possible when filesystem crawling step has finished.

During synchronization, you can press CTRL-C to interrupt the process. The first CTRL-C prevents new
synchronizations from being submitted and the process will wait for current synchronizations to be
finished before exiting. If you press CTRL-C again, current synchronizations will be killed and fpsync
will exit immediately. When using option -E to enable directory mode and rsync's --delete option, keep
in mind that killing rsync processes may lead to a situation where certain files have been updated and
others not deleted yet (because the deletion process is postponed using rsync's --delete-after option).

On certain systems, CTRL-T can be pressed to get the status of current and remaining parts to be
synchronized. This can also be achieved by sending a SIGINFO to the fpsync process.

Whether you use verbose mode or not, everything is logged within shdir/log/.

EXAMPLES

       Here are some examples:

       fpsync -n 4 /usr/src/ /var/src/

               Synchronizes /usr/src/ to /var/src/ using 4 local jobs.

       fpsync -n 2 -w login@machine1 -w login@machine2 -d /mnt/fpsync /mnt/src/ /mnt/dst/

               Synchronizes  /mnt/src/  to  /mnt/dst/ using 2 concurrent jobs executed remotely on 2 SSH workers
               (machine1 and machine2).  The shared directory is set to /mnt/fpsync and mounted on  the  machine
               running  fpsync,  as  well as on machine1 and machine2.  The source directory (/mnt/src/) is also
               available on those 3 machines, while the destination directory  (/mnt/dst/)  is  mounted  on  SSH
               workers only (machine1 and machine2).

LIMITATIONS

Parallelizing rsync(1) can make several options not usable, such as --delete. If your source directory
is live while fpsync is running, you will have to delete extra files from destination directory. This is
traditionally done by using a final -offline- rsync(1) pass that will use this option, but you can also
use fpsync and option -E to perform the same task using several workers.

fpsync enqueues synchronization jobs on disk, within the tmpdir/queue directory. Be careful to host this
queue on a filesystem that can handle fine-grained mtime timestamps (i.e. with a sub-second precision) if
you want the queue to be processed in order when fpart(1) generates several jobs per second. On FreeBSD,
VFS(9) timestamps' precision can be tuned using the 'vfs.timestamp_precision' sysctl. See
vfs_timestamp(9).

Contrary to rsync(1), fpsync enforces the final '/' on the source directory. It means that directory
contents are synchronized, not the source directory itself (i.e. you will not get a subdirectory of the
name of the source directory in the target directory after synchronization).

Before starting filesystem crawling, fpsync changes its current working directory to src_dir/ and
generates partitions containing relative paths (all starting with './'). This is important to keep in
mind when modifying toolopts or fpartopts dealing with file or directory paths.

If you want to run fpsync in the background, your shell must support enabling job control without a tty
in non-interactive mode. As of this writing, Dash does not support that feature and will send a SIGTTIN
to the whole process group, suspending fpsync execution.

AUTHOR, AVAILABILITY

       Fpsync  has  been  written  by  Ganaël  LAPLANCHE  and  is   available   under   the   BSD   license   on
       http://contribs.martymac.org

BUGS

       No bug known (yet).

Debian                                          January 27, 2015                                       FPSYNC(1)