DOKK / manpages / debian 12 / borgbackup2 / borg2-import-tar.1.en
BORG-IMPORT-TAR(1) borg backup tool BORG-IMPORT-TAR(1)

borg-import-tar - Create a backup archive from a tarball

borg [common options] import-tar [options] NAME TARFILE

This command creates a backup archive from a tarball.

When giving '-' as path, Borg will read a tar stream from standard input.

By default (--tar-filter=auto) Borg will detect whether the file is compressed based on its file extension and pipe the file through an appropriate filter:

  • .tar.gz or .tgz: gzip -d
  • .tar.bz2 or .tbz: bzip2 -d
  • .tar.xz or .txz: xz -d
  • .tar.zstd or .tar.zst: zstd -d
  • .tar.lz4: lz4 -d

Alternatively, a --tar-filter program may be explicitly specified. It should read compressed data from stdin and output an uncompressed tar stream on stdout.

Most documentation of borg create applies. Note that this command does not support excluding files.

A --sparse option (as found in borg create) is not supported.

About tar formats and metadata conservation or loss, please see borg export-tar.

import-tar reads these tar formats:

  • BORG: borg specific (PAX-based)
  • PAX: POSIX.1-2001
  • GNU: GNU tar
  • POSIX.1-1988 (ustar)
  • UNIX V7 tar
  • SunOS tar with extended attributes

See borg-common(1) for common options of Borg commands.

specify the archive name
input tar file. "-" to read from stdin instead.

filter program to pipe data through
print statistics for the created archive
output verbose list of items (files, dirs, ...)
only display items with the given status characters
output stats as JSON (implies --stats)

add a comment text to the archive
manually specify the archive creation date/time (yyyy-mm-ddThh:mm:ss[(+|-)HH:MM] format, (+|-)HH:MM is the UTC offset, default: local time zone). Alternatively, give a reference file/directory.
write checkpoint every SECONDS seconds (Default: 1800)
write checkpoint every BYTES bytes (Default: 0, meaning no volume based checkpointing)
specify the chunker parameters (ALGO, CHUNK_MIN_EXP, CHUNK_MAX_EXP, HASH_MASK_BITS, HASH_WINDOW_SIZE). default: buzhash,19,23,21,4095
select compression algorithm, see the output of the "borg help compression" command for details.

# export as uncompressed tar
$ borg export-tar Monday Monday.tar
# import an uncompressed tar
$ borg import-tar Monday Monday.tar
# exclude some file types, compress using gzip
$ borg export-tar Monday Monday.tar.gz --exclude '*.so'
# use higher compression level with gzip
$ borg export-tar --tar-filter="gzip -9" Monday Monday.tar.gz
# copy an archive from repoA to repoB
$ borg -r repoA export-tar --tar-format=BORG archive - | borg -r repoB import-tar archive -
# export a tar, but instead of storing it on disk, upload it to remote site using curl
$ borg export-tar Monday - | curl --data-binary @- https://somewhere/to/POST
# remote extraction via "tarpipe"
$ borg export-tar Monday - | ssh somewhere "cd extracted; tar x"


Outputs a script that copies all archives from repo1 to repo2:

for A T in `borg list --format='{archive} {time:%Y-%m-%dT%H:%M:%S}{NL}'`
do


  echo "borg -r repo1 export-tar --tar-format=BORG $A - | borg -r repo2 import-tar --timestamp=$T $A -"
done


Kept:

  • archive name, archive timestamp
  • archive contents (all items with metadata and data)

Lost:

•
some archive metadata (like the original commandline, execution time, etc.)

Please note:

  • all data goes over that pipe, again and again for every archive
  • the pipe is dumb, there is no data or transfer time reduction there due to deduplication
  • maybe add compression
  • pipe over ssh for remote transfer
  • no special sparse file support

borg-common(1)

The Borg Collective

2023-03-01