chkbit checks the data integrity of your files
chkbit is a lightweight tool to check the data integrity of your files. It allows you to verify that the data has not changed since you put it there and that it is still the same when you move it somewhere else.
On your Disk
chkbit starts with your primary disk. It creates checksums for each folder that will follow your data onto your backups.
Even though your filesystems should have built in checksums, it is usually not trivial to take them onto another media.
On your backup
No matter what storage media or filesystem you use, chkbit stores its indexes in hidden files that are backed up together with your data.
When you run chkbit-verify on your backup media you can make sure that every byte was correctly transferred.
If your backup media fails or experiences bitrot/data degradation, chkbit allows you to discover what files were damaged and need to be replaced by other backups.
Data in the Cloud
Some cloud providers re-encode your videos or compress your images to save space. chkbit will alert you of any changes.
pip install --user chkbit
Or in its own environment:
pipx install chkbit
chkbit -u PATH to create/update the chkbit index.
- create a
.chkbitindex in every subdirectory of the path it was given.
- update the index with md5/sha512 hashes for every file.
- report damage for files that failed the integrity check since the last run (check the exit status).
chkbit PATH to verify only.
usage: chkbit.py [-h] [-u] [--algo ALGO] [-f] [-i] [-s] [-w N] [-q] [-v] [PATH ...] Checks the data integrity of your files. See https://github.com/laktak/chkbit-py positional arguments: PATH directories to check options: -h, --help show this help message and exit -u, --update update indices (without this chkbit will only verify files) --algo ALGO hash algorithm: md5, sha512 -f, --force force update of damaged items -i, --verify-index verify files in the index only (will not report new files) -s, --skip-symlinks do not follow symlinks -w N, --workers N number of workers to use, default=5 -q, --quiet quiet, don't show progress/information -v, --verbose verbose output Status codes: DMG: error, data damage detected EIX: error, index damaged old: warning, file replaced by an older version new: new file upd: file updated ok : check ok skp: skipped (see .chkbitignore) EXC: internal exception
chkbit is set to use only 5 workers by default so it will not slow your system to a crawl. You can specify a higher number to make it a lot faster (requires about 128kB of memory per worker).
chkbit cannot repair damage, its job is simply to detect it.
- backup regularly.
- run chkbit before each backup.
- check for damage on the backup media.
- in case of damage restore from a checked backup.
.chkbitignore file containing the names of the files/directories you wish to ignore
- each line should contain exactly one name
- lines starting with
- you may use Unix shell-style wildcards
Should I run
chkbit on my whole drive?
You would typically run it only on content that you keep for a long time (e.g. your pictures, music, videos).
Why is chkbit placing the index in
.chkbit files (vs a database)?
The advantage of the .chkbit files is that
- when you move a directory the index moves with it
- when you make a backup the index is also backed up
The disadvantage is obviously that you get hidden
.chkbit files in your content folders.
How does chkbit work?
chkbit operates on files.
When run for the first time it records a hash of the file contents as well as the file modification time.
When you run it again it first checks the modification time,
- if the time changed (because you made an edit) it records a new hash.
- otherwise it will compare the current hash to the recorded value and report an error if they do not match.
I wish to use a stronger hash algorithm
chkbit now supports sha512. You can specify it with
Note that existing index files will use the hash that they were created with. If you wish to update all hashes you need to delete your existing indexes first.
How can I delete the index files?
List them with
find . -name .chkbit
-delete to delete.
Can I test if chkbit is working correctly?
On Linux/OS X you can try:
Create test and set the modified time:
$ echo foo1 > test; touch -t 201501010000 test $ chkbit -u . add ./test Processed 1 file(s). Indices were updated.
add indicates the file was added.
Now update test with a new modified:
$ echo foo2 > test; touch -t 201501010001 test # update test & modified $ chkbit -u . upd ./test Processed 1 file(s). Indices were updated.
upd indicates the file was updated.
Now update test with the same modified to simulate damage:
$ echo foo3 > test; touch -t 201501010001 test $ chkbit -u . DMG ./test Processed 0 file(s). chkbit detected damage in these files: ./test error: detected 1 file(s) with damage!
DMG indicates damage.
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