mirror/borg
1
0
Fork 0
mirror of https://github.com/borgbackup/borg.git synced 2025-01-01 12:45:34 +00:00
Code Issues Releases Wiki Activity

check: update comment / help

Browse source
This commit is contained in:
Thomas Waldmann 2024-08-23 14:22:23 +02:00
parent d9f24def6a
commit 2be98c773b
No known key found for this signature in database
GPG key ID: 243ACFA951F78E01
1 changed files with 10 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

25
src/borg/archiver/check_cmd.py
View file

@ -38,9 +38,7 @@ def do_check(self, args, repository):
if args.repair and args.max_duration: if args.repair and args.max_duration:
raise CommandError("--repair does not allow --max-duration argument.") raise CommandError("--repair does not allow --max-duration argument.")
if args.max_duration and not args.repo_only: if args.max_duration and not args.repo_only:
# when doing a partial repo check, we can only check crc32 checksums in segment files, # when doing a partial repo check, we can only check xxh64 hashes in repository files.
# we can't build a fresh repo index in memory to verify the on-disk index against it.
# thus, we should not do an archives check based on a unknown-quality on-disk repo index.
# also, there is no max_duration support in the archives check code anyway. # also, there is no max_duration support in the archives check code anyway.
raise CommandError("--repository-only is required for --max-duration support.") raise CommandError("--repository-only is required for --max-duration support.")
if not args.archives_only: if not args.archives_only:
@ -72,8 +70,8 @@ def build_parser_check(self, subparsers, common_parser, mid_common_parser):
It consists of two major steps: It consists of two major steps:
1. Checking the consistency of the repository itself. This includes checking 1. Checking the consistency of the repository itself. This includes checking
the segment magic headers, and both the metadata and data of all objects in the file magic headers, and both the metadata and data of all objects in
the segments. The read data is checked by size and CRC. Bit rot and other the repository. The read data is checked by size and hash. Bit rot and other
types of accidental damage can be detected this way. Running the repository types of accidental damage can be detected this way. Running the repository
check can be split into multiple partial checks using ``--max-duration``. check can be split into multiple partial checks using ``--max-duration``.
When checking a remote repository, please note that the checks run on the When checking a remote repository, please note that the checks run on the
@ -108,13 +106,12 @@ def build_parser_check(self, subparsers, common_parser, mid_common_parser):
**Warning:** Please note that partial repository checks (i.e. running it with **Warning:** Please note that partial repository checks (i.e. running it with
``--max-duration``) can only perform non-cryptographic checksum checks on the ``--max-duration``) can only perform non-cryptographic checksum checks on the
segment files. A full repository check (i.e. without ``--max-duration``) can repository files. Enabling partial repository checks excepts archive checks
also do a repository index check. Enabling partial repository checks excepts for the same reason. Therefore partial checks may be useful with very large
archive checks for the same reason. Therefore partial checks may be useful with repositories only where a full check would take too long.
very large repositories only where a full check would take too long.
The ``--verify-data`` option will perform a full integrity verification (as The ``--verify-data`` option will perform a full integrity verification (as
opposed to checking the CRC32 of the segment) of data, which means reading the opposed to checking just the xxh64) of data, which means reading the
data from the repository, decrypting and decompressing it. It is a complete data from the repository, decrypting and decompressing it. It is a complete
cryptographic verification and hence very time consuming, but will detect any cryptographic verification and hence very time consuming, but will detect any
accidental and malicious corruption. Tamper-resistance is only guaranteed for accidental and malicious corruption. Tamper-resistance is only guaranteed for
@ -151,17 +148,15 @@ def build_parser_check(self, subparsers, common_parser, mid_common_parser):
In practice, repair mode hooks into both the repository and archive checks: In practice, repair mode hooks into both the repository and archive checks:
1. When checking the repository's consistency, repair mode will try to recover 1. When checking the repository's consistency, repair mode removes corrupted
as many objects from segments with integrity errors as possible, and ensure objects from the repository after it did a 2nd try to read them correctly.
that the index is consistent with the data stored in the segments.
2. When checking the consistency and correctness of archives, repair mode might 2. When checking the consistency and correctness of archives, repair mode might
remove whole archives from the manifest if their archive metadata chunk is remove whole archives from the manifest if their archive metadata chunk is
corrupt or lost. On a chunk level (i.e. the contents of files), repair mode corrupt or lost. On a chunk level (i.e. the contents of files), repair mode
will replace corrupt or lost chunks with a same-size replacement chunk of will replace corrupt or lost chunks with a same-size replacement chunk of
zeroes. If a previously zeroed chunk reappears, repair mode will restore zeroes. If a previously zeroed chunk reappears, repair mode will restore
this lost chunk using the new chunk. Lastly, repair mode will also delete this lost chunk using the new chunk.
orphaned chunks (e.g. caused by read errors while creating the archive).
Most steps taken by repair mode have a one-time effect on the repository, like Most steps taken by repair mode have a one-time effect on the repository, like
removing a lost archive from the repository. However, replacing a corrupt or removing a lost archive from the repository. However, replacing a corrupt or