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BORG-TRANSFER(1) borg backup tool BORG-TRANSFER(1)

NAME

borg-transfer - archives transfer from other repository, optionally upgrade data format

SYNOPSIS

borg [common options] transfer [options]

DESCRIPTION

This command transfers archives from one repository to another repository. Optionally, it can also upgrade the transferred data. Optionally, it can also recompress the transferred data.

It is easiest (and fastest) to give --compression=COMPRESSION --recompress=never using the same COMPRESSION mode as in the SRC_REPO - borg will use that COMPRESSION for metadata (in any case) and keep data compressed "as is" (saves time as no data compression is needed).

If you want to globally change compression while transferring archives to the DST_REPO, give --compress=WANTED_COMPRESSION --recompress=always.

Suggested use for general purpose archive transfer (not repo upgrades):

# create a related DST_REPO (reusing key material from SRC_REPO), so that
# chunking and chunk id generation will work in the same way as before.
borg --repo=DST_REPO rcreate --other-repo=SRC_REPO --encryption=DST_ENC
# transfer archives from SRC_REPO to DST_REPO
borg --repo=DST_REPO transfer --other-repo=SRC_REPO --dry-run  # check what it would do
borg --repo=DST_REPO transfer --other-repo=SRC_REPO            # do it!
borg --repo=DST_REPO transfer --other-repo=SRC_REPO --dry-run  # check! anything left?


The default is to transfer all archives, including checkpoint archives.

You could use the misc. archive filter options to limit which archives it will transfer, e.g. using the -a option. This is recommended for big repositories with multiple data sets to keep the runtime per invocation lower.

For repository upgrades (e.g. from a borg 1.2 repo to a related borg 2.0 repo), usage is quite similar to the above:

# fast: compress metadata with zstd,3, but keep data chunks compressed as they are:
borg --repo=DST_REPO transfer --other-repo=SRC_REPO --upgrader=From12To20 \


     --compress=zstd,3 --recompress=never
# compress metadata and recompress data with zstd,3
borg --repo=DST_REPO transfer --other-repo=SRC_REPO --upgrader=From12To20 \


     --compress=zstd,3 --recompress=always


OPTIONS

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

options

do not change repository, just check
transfer archives from the other repository
use the upgrader to convert transferred data (default: no conversion)
select compression algorithm, see the output of the "borg help compression" command for details.
recompress data chunks according to MODE and --compression. Possible modes are always: recompress unconditionally; and never: do not recompress (faster: re-uses compressed data chunks w/o change).If no MODE is given, always will be used. Not passing --recompress is equivalent to "--recompress never".

Archive filters

only consider archive names matching the pattern. see "borg help match-archives".
Comma-separated list of sorting keys; valid keys are: timestamp, archive, name, id; default is: timestamp
consider first N archives after other filters were applied
consider last N archives after other filters were applied
consider archives between the oldest archive's timestamp and (oldest + TIMESPAN), e.g. 7d or 12m.
consider archives between the newest archive's timestamp and (newest - TIMESPAN), e.g. 7d or 12m.
consider archives older than (now - TIMESPAN), e.g. 7d or 12m.
consider archives newer than (now - TIMESPAN), e.g. 7d or 12m.

EXAMPLES

# 0. Have borg 2.0 installed on client AND server, have a b12 repo copy for testing.
# 1. Create a new "related" repository:
# here, the existing borg 1.2 repo used repokey-blake2 (and aes-ctr mode),
# thus we use repokey-blake2-aes-ocb for the new borg 2.0 repo.
# staying with the same chunk id algorithm (blake2) and with the same
# key material (via --other-repo <oldrepo>) will make deduplication work
# between old archives (copied with borg transfer) and future ones.
# the AEAD cipher does not matter (everything must be re-encrypted and
# re-authenticated anyway), you could also choose repokey-blake2-chacha20-poly1305.
# in case your old borg repo did not use blake2, just remove the "-blake2".
$ borg --repo       ssh://borg2@borgbackup/./tests/b20 rcreate \


       --other-repo ssh://borg2@borgbackup/./tests/b12 -e repokey-blake2-aes-ocb
# 2. Check what and how much it would transfer:
$ borg --repo       ssh://borg2@borgbackup/./tests/b20 transfer --upgrader=From12To20 \


       --other-repo ssh://borg2@borgbackup/./tests/b12 --dry-run
# 3. Transfer (copy) archives from old repo into new repo (takes time and space!):
$ borg --repo       ssh://borg2@borgbackup/./tests/b20 transfer --upgrader=From12To20 \


       --other-repo ssh://borg2@borgbackup/./tests/b12
# 4. Check if we have everything (same as 2.):
$ borg --repo       ssh://borg2@borgbackup/./tests/b20 transfer --upgrader=From12To20 \


       --other-repo ssh://borg2@borgbackup/./tests/b12 --dry-run


SEE ALSO

borg-common(1)

AUTHOR

The Borg Collective

2024-03-09