How to Transfer Files with Rsync over SSH – Google Cloud

How to Transfer Files with Rsync over SSH – Google Cloud. Rsync is one of the most important tool in mirroring data, copying files to remote systems or servers. This tool has more functions compared to scp, sftp and ftp.

In this guide you are going to learn how to transfer files using Rsync to any servers.

This setup is tested on Google Cloud Platform.

In some servers you will have rsync installed by default. If you don’t have rsync installed you can install it using the following command.

Prerequisites

• SSH access to the server with read and write permissions.
• If you are using this on Google Cloud, you need to setup SSH keys. You can follow this guide to setup SSH keys from Windows machine.

Ubuntu and Debian

 sudo apt install rsync 

CentOS and Fedora

 sudo yum install rsync 

Setup Permissions on Target server

If you don’t have enough permissions for the current user you can provide permissions using the acl command on the directories and provide the appropriate permissions.

If you dont have acl installed you can use the below command to install ACL.

sudo apt install acl

Once you have acl installed you can execute the following command to setup permissions on the target or remote server.

sudo setfacl -R -m u:username:rwx /path/to/your/folder

Transfer Files using Rsync with SSH Password

You can simply use the following command to use the password based authentication.

rsync -a -e ssh path/to/source-files username@External_IP:/path/in/the/target-server

Once this command is executed you will be prompted to enter the password of the user.

Transfer Files using Rsync with SSH Keys

This is the syntax of the rsync command for transferring files using Rsync with public and private key based authentication.

Make sure you have added the public key to the target server.

rsync -a -e "ssh -i path/to/private-key" path/to/source-files username@External_IP:/path/in/the/target-server

General Details of Rsync

Generally if the file exists on the remote server it will get overwritten.

There are many options you can use, in the above command we are using -a option which syncs directories recursively, transfer special and block devices, preserve symbolic links, modification times, group, ownership, and permissions.

By default Rsync with SSH uses the standard SSH port 22, if you are using a different port for your SSH you need to specify the port using the -p option.

rsync -a -e "ssh -p port" path/to/source-files username@External_IP:/path/in/the/target-server

Options Summary

Here is a short summary of the options available in rsync. Please refer to the detailed description below for a complete description.

-v, --verbose               increase verbosity
-q, --quiet                 suppress non-error messages
    --no-motd               suppress daemon-mode MOTD (see 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         backup suffix (default ~ w/o --backup-dir)
-u, --update                skip files that are newer on the receiver
    --inplace               update destination files in-place
    --append                append data onto shorter files
    --append-verify         --append w/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 tree
-k, --copy-dirlinks         transform symlink to 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 executability
    --chmod=CHMOD           affect file and/or directory permissions
-A, --acls                  preserve ACLs (implies -p)
-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
    --super                 receiver attempts super-user activities
    --fake-super            store/recover privileged attrs using xattrs
-S, --sparse                handle sparse files efficiently
-n, --dry-run               perform a trial run with no changes made
-W, --whole-file            copy files whole (w/o delta-xfer algorithm)
-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 remote machine
    --existing              skip creating new files on receiver
    --ignore-existing       skip updating files that exist on receiver
    --remove-source-files   sender removes synchronized files (non-dir)
    --del                   an alias for --delete-during
    --delete                delete extraneous files from dest dirs
    --delete-before         receiver deletes before transfer (default)
    --delete-during         receiver deletes during xfer, not before
    --delete-delay          find deletions during, delete after
    --delete-after          receiver deletes after transfer, not before
    --delete-excluded       also delete excluded files from dest dirs
    --ignore-errors         delete even if there are I/O errors
    --force                 force deletion of dirs 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 end
-m, --prune-empty-dirs      prune empty directory chains from file-list
    --numeric-ids           don't map uid/gid values by user/group name
    --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 size and time
    --size-only             skip files that match in size
    --modify-window=NUM     compare mod-times with reduced accuracy
-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 received 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 suffix in LIST
-C, --cvs-exclude           auto-ignore files in 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; wildcard chars only
    --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=KBPS          limit I/O bandwidth; KBytes per second
    --write-batch=FILE      write a batched update to FILE
    --only-write-batch=FILE like --write-batch but w/o updating dest
    --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 (see below for -h comment)

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Conclusion

Now you have learned how to use Rsync to transfer files to and from your server.

Thanks for your time. If you face any problem or any feedback, please leave a comment below.