rsync
rsync is a powerful file sync program capable of efficient file transfers and directory synchronization.
rsync is included at the system set on all Gentoo profiles has been used as the primary method for syncing the Gentoo ebuild repository since Gentoo was created.
Installation
USE flags
USE flags for net-misc/rsync File transfer program to keep remote files into sync
acl
|
Add support for Access Control Lists |
examples
|
Install examples, usually source code |
iconv
|
Enable support for the iconv character set conversion library |
lz4
|
Enable support for lz4 compression (as implemented in app-arch/lz4) |
rrsync
|
Install rrsync script to setup restricted rsync users via ssh logins |
ssl
|
Add support for SSL/TLS connections (Secure Socket Layer / Transport Layer Security) |
stunnel
|
Provide helper scripts for using rsync via >=net-misc/stunnel-4 |
system-zlib
|
Use system zlib instead of bundled one. This is incompatible with older rsync releases! |
verify-sig
|
Verify upstream signatures on distfiles |
xattr
|
Add support for extended attributes (filesystem-stored metadata) |
xxhash
|
Enable dev-libs/xxhash support for hashing |
zstd
|
Enable support for ZSTD compression |
Emerge
root #
emerge --ask --oneshot net-misc/rsync
Configuration
rsync can run both as a client or a server.
Files
- /etc/rsyncd.conf - rsync's configuration file for daemon mode.
- See man 5 rsyncd.conf for more configuration options.
Service
Daemon help can be seen by running:
root #
rsync --daemon --help
rsync version 3.1.3 protocol version 31 Copyright (C) 1996-2018 by Andrew Tridgell, Wayne Davison, and others. Web site: http://rsync.samba.org/ Capabilities: 64-bit files, 64-bit inums, 64-bit timestamps, 64-bit long ints, socketpairs, hardlinks, symlinks, IPv6, batchfiles, inplace, append, ACLs, xattrs, iconv, symtimes, prealloc rsync comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to redistribute it under certain conditions. See the GNU General Public Licence for details. Usage: rsync --daemon [OPTION]... --address=ADDRESS bind to the specified address --bwlimit=RATE limit socket I/O bandwidth --config=FILE specify alternate rsyncd.conf file -M, --dparam=OVERRIDE override global daemon config parameter --no-detach do not detach from the parent --port=PORT listen on alternate port number --log-file=FILE override the "log file" setting --log-file-format=FMT override the "log format" setting --sockopts=OPTIONS specify custom TCP options -v, --verbose increase verbosity -4, --ipv4 prefer IPv4 -6, --ipv6 prefer IPv6 --help show this help screen If you were not trying to invoke rsync as a daemon, avoid using any of the daemon-specific rsync options. See also the rsyncd.conf(5) man page.
OpenRC
To enable the service to run at system boot:
root #
rc-update add rsyncd default
To start the rsync daemon now:
root #
rc-service rsyncd start
systemd
To enable the service to run at system boot:
root #
systemctl enable rsyncd.service
To start the rsync daemon now:
root #
systemctl start rsyncd.service
Examples
Sharing from a list of files
...
# use chroot = no # Needed when crossing filesystem boundaries. - #
...
# hosts allow = 192.168.0.0/16 # Allow local network. - #
# hosts deny = * # Deny the rest. - #
...
# uid = root # Needed for files like /etc/ssh/sshd_config. - #
# gid = root # >> /etc/sudoers. - #
...
[sync]
path = /
include from = /backup.list # List of files to copy. - #
exclude = * # Exclude the rest. - #
In the file list, all the intermediary paths are necessary, except when the ***
wildcard is used.
/etc/
/etc/conf.d/
/etc/conf.d/hwclock
/etc/fonts/***
Synchronizing Gentoo's repository between local machines
If several Gentoo systems are in the same network, it spares bandwidth for everyone to define a local server for the main ebuild repository instead of letting all the machines synchronize in turn with the same external mirror.
The version of /etc/rsyncd.conf shipped by Gentoo already provides a valid default configuration. Uncomment the following lines:
[gentoo-portage]
path = /var/db/repos/gentoo
comment = Gentoo ebuild repository
exclude = /distfiles /packages
Then, start the rsync daemon on the server.
Finally, change the repository configuration on client machines to match the address of the local server. For example, if this address is 192.168.2.24:
[gentoo]
#sync-uri = rsync://rsync.gentoo.org/gentoo-portage
sync-uri = rsync://192.168.2.24/gentoo-portage
The usual commands emerge --sync or emaint sync -r gentoo function normally and the process is usually much faster. The change can be reversed at any time.
Usage
Invocation
Client invocation:
user $
rsync --help
rsync version 3.1.3 protocol version 31 Copyright (C) 1996-2018 by Andrew Tridgell, Wayne Davison, and others. Web site: http://rsync.samba.org/ Capabilities: 64-bit files, 64-bit inums, 64-bit timestamps, 64-bit long ints, socketpairs, hardlinks, symlinks, IPv6, batchfiles, inplace, append, ACLs, xattrs, iconv, symtimes, prealloc rsync comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to redistribute it under certain conditions. See the GNU General Public Licence for details. rsync is a file transfer program capable of efficient remote update via a fast differencing algorithm. Usage: rsync [OPTION]... SRC [SRC]... DEST or rsync [OPTION]... SRC [SRC]... [USER@]HOST:DEST or rsync [OPTION]... SRC [SRC]... [USER@]HOST::DEST or rsync [OPTION]... SRC [SRC]... rsync://[USER@]HOST[:PORT]/DEST or rsync [OPTION]... [USER@]HOST:SRC [DEST] or rsync [OPTION]... [USER@]HOST::SRC [DEST] or rsync [OPTION]... rsync://[USER@]HOST[:PORT]/SRC [DEST] The ':' usages connect via remote shell, while '::' & 'rsync://' usages connect to an rsync daemon, and require SRC or DEST to start with a module name. Options -v, --verbose increase verbosity --info=FLAGS fine-grained informational verbosity --debug=FLAGS fine-grained debug verbosity --msgs2stderr special output handling for debugging -q, --quiet suppress non-error messages --no-motd suppress daemon-mode MOTD (see manpage caveat) -c, --checksum skip based on checksum, not mod-time & size -a, --archive archive mode; equals -rlptgoD (no -H,-A,-X) --no-OPTION turn off an implied OPTION (e.g. --no-D) -r, --recursive recurse into directories -R, --relative use relative path names --no-implied-dirs don't send implied dirs with --relative -b, --backup make backups (see --suffix & --backup-dir) --backup-dir=DIR make backups into hierarchy based in DIR --suffix=SUFFIX set backup suffix (default ~ w/o --backup-dir) -u, --update skip files that are newer on the receiver --inplace update destination files in-place (SEE MAN PAGE) --append append data onto shorter files --append-verify like --append, but with old data in file checksum -d, --dirs transfer directories without recursing -l, --links copy symlinks as symlinks -L, --copy-links transform symlink into referent file/dir --copy-unsafe-links only "unsafe" symlinks are transformed --safe-links ignore symlinks that point outside the source tree --munge-links munge symlinks to make them safer (but unusable) -k, --copy-dirlinks transform symlink to a dir into referent dir -K, --keep-dirlinks treat symlinked dir on receiver as dir -H, --hard-links preserve hard links -p, --perms preserve permissions -E, --executability preserve the file's executability --chmod=CHMOD affect file and/or directory permissions -A, --acls preserve ACLs (implies --perms) -X, --xattrs preserve extended attributes -o, --owner preserve owner (super-user only) -g, --group preserve group --devices preserve device files (super-user only) --specials preserve special files -D same as --devices --specials -t, --times preserve modification times -O, --omit-dir-times omit directories from --times -J, --omit-link-times omit symlinks from --times --super receiver attempts super-user activities --fake-super store/recover privileged attrs using xattrs -S, --sparse turn sequences of nulls into sparse blocks --preallocate allocate dest files before writing them -n, --dry-run perform a trial run with no changes made -W, --whole-file copy files whole (without delta-xfer algorithm) --checksum-choice=STR choose the checksum algorithms -x, --one-file-system don't cross filesystem boundaries -B, --block-size=SIZE force a fixed checksum block-size -e, --rsh=COMMAND specify the remote shell to use --rsync-path=PROGRAM specify the rsync to run on the remote machine --existing skip creating new files on receiver --ignore-existing skip updating files that already exist on receiver --remove-source-files sender removes synchronized files (non-dirs) --del an alias for --delete-during --delete delete extraneous files from destination dirs --delete-before receiver deletes before transfer, not during --delete-during receiver deletes during the transfer --delete-delay find deletions during, delete after --delete-after receiver deletes after transfer, not during --delete-excluded also delete excluded files from destination dirs --ignore-missing-args ignore missing source args without error --delete-missing-args delete missing source args from destination --ignore-errors delete even if there are I/O errors --force force deletion of directories even if not empty --max-delete=NUM don't delete more than NUM files --max-size=SIZE don't transfer any file larger than SIZE --min-size=SIZE don't transfer any file smaller than SIZE --partial keep partially transferred files --partial-dir=DIR put a partially transferred file into DIR --delay-updates put all updated files into place at transfer's end -m, --prune-empty-dirs prune empty directory chains from the file-list --numeric-ids don't map uid/gid values by user/group name --usermap=STRING custom username mapping --groupmap=STRING custom groupname mapping --chown=USER:GROUP simple username/groupname mapping --timeout=SECONDS set I/O timeout in seconds --contimeout=SECONDS set daemon connection timeout in seconds -I, --ignore-times don't skip files that match in size and mod-time -M, --remote-option=OPTION send OPTION to the remote side only --size-only skip files that match in size -@, --modify-window=NUM set the accuracy for mod-time comparisons -T, --temp-dir=DIR create temporary files in directory DIR -y, --fuzzy find similar file for basis if no dest file --compare-dest=DIR also compare destination files relative to DIR --copy-dest=DIR ... and include copies of unchanged files --link-dest=DIR hardlink to files in DIR when unchanged -z, --compress compress file data during the transfer --compress-level=NUM explicitly set compression level --skip-compress=LIST skip compressing files with a suffix in LIST -C, --cvs-exclude auto-ignore files the same way CVS does -f, --filter=RULE add a file-filtering RULE -F same as --filter='dir-merge /.rsync-filter' repeated: --filter='- .rsync-filter' --exclude=PATTERN exclude files matching PATTERN --exclude-from=FILE read exclude patterns from FILE --include=PATTERN don't exclude files matching PATTERN --include-from=FILE read include patterns from FILE --files-from=FILE read list of source-file names from FILE -0, --from0 all *-from/filter files are delimited by 0s -s, --protect-args no space-splitting; only wildcard special-chars --address=ADDRESS bind address for outgoing socket to daemon --port=PORT specify double-colon alternate port number --sockopts=OPTIONS specify custom TCP options --blocking-io use blocking I/O for the remote shell --stats give some file-transfer stats -8, --8-bit-output leave high-bit chars unescaped in output -h, --human-readable output numbers in a human-readable format --progress show progress during transfer -P same as --partial --progress -i, --itemize-changes output a change-summary for all updates --out-format=FORMAT output updates using the specified FORMAT --log-file=FILE log what we're doing to the specified FILE --log-file-format=FMT log updates using the specified FMT --password-file=FILE read daemon-access password from FILE --list-only list the files instead of copying them --bwlimit=RATE limit socket I/O bandwidth --outbuf=N|L|B set output buffering to None, Line, or Block --write-batch=FILE write a batched update to FILE --only-write-batch=FILE like --write-batch but w/o updating destination --read-batch=FILE read a batched update from FILE --protocol=NUM force an older protocol version to be used --iconv=CONVERT_SPEC request charset conversion of filenames --checksum-seed=NUM set block/file checksum seed (advanced) -4, --ipv4 prefer IPv4 -6, --ipv6 prefer IPv6 --version print version number (-h) --help show this help (-h is --help only if used alone) Use "rsync --daemon --help" to see the daemon-mode command-line options. Please see the rsync(1) and rsyncd.conf(5) man pages for full documentation. See http://rsync.samba.org/ for updates, bug reports, and answers
Backuping
Rsync is a good tool for the full system backup (but please use git for specific configs and data), because if only a few files were changes - only them will occupy space inside the next backup folder - thanks to hardlinking.
In order to make a backup:
BEFORE=$(df -h)
STARTED=$(date)
DATE=`date "+%Y-%m-%d"`
DEST="/mnt/backup/$DATE"
rsync --archive --acls --xattrs --delete --progress --verbose --exclude-from=exclude.txt --link-dest=/mnt/backup/last --mkpath / $DEST
ln --symbolic --force --no-dereference $DATE /mnt/backup/last
echo "Started at: " $STARTED
echo "Current time: " $(date)
echo "Before:
$BEFORE
Now:
"
df -h
In the same folder you can have exclude list:
/dev/*
/proc/*
/sys/*
/run/*
/var/db/repos/gentoo
/var/db/repos/guru
/tmp/*
/var/tmp
/lost+found
/mnt/*
/home/vitaly/.npm
/home/vitaly/.cache
/home/vitaly/go/pkg/mod/cache
So your backups will looks like this:
user $
ls -lh
total 40K drwxr-xr-x 20 root root 4.0K Oct 14 23:52 2022-09-28 drwxr-xr-x 20 root root 4.0K Oct 14 23:58 2022-10-14 drwxr-xr-x 20 root root 4.0K Oct 15 00:34 2022-10-15 drwxr-xr-x 20 root root 4.0K Oct 15 00:34 2022-11-06 drwxr-xr-x 20 root root 4.0K Oct 15 00:34 2022-11-19 drwxr-xr-x 20 root root 4.0K Oct 15 00:34 2022-12-03 drwxr-xr-x 20 root root 4.0K Oct 15 00:34 2022-12-10 drwxr-xr-x 20 root root 4.0K Oct 15 00:34 2022-12-17 drwxr-xr-x 20 root root 4.0K Oct 15 00:34 2022-12-24 drwxr-xr-x 20 root root 4.0K Oct 15 00:34 2023-01-03 lrwxrwxrwx 1 root root 10 Jan 3 15:27 last -> 2023-01-03
How to restore from such backup:
root #
rsync --archive --acls --xattrs --progress --verbose . /mnt
On the new SSD you probably will need to install the bootloader, or alter UUID values in /etc/fstab.
See more at https://wiki.archlinux.org/title/rsync#Snapshot_backup
Troubleshooting
rsync daemon stops working after glibc build
Occasionally the rsync daemon will stop working after glibc has been rebuilt. The error on the client side (when trying to sync from the server) will be something like the following:
@ERROR: invalid uid nobody rsync error: error starting client-server protocol (code 5) at main.c(1657) [Receiver=3.1.3]
Unfortunately simply restarting the rsync daemon will not fix the issue.
The solution, found in bug #414843, is to rebuild the net-misc/rsync package so that it can re-link against the proper version of glibc's libc.so.6 file.
root #
emerge --ask --oneshot net-misc/rsync
After the rebuild then restart the daemon.
See also
- Portage — the official package manager and distribution system for Gentoo.
- Ssh — the ubiquitous tool for logging into and working on remote machines securely.
- csync2 — a tool for asynchronous file synchronization in clusters.