diff --git a/docs/faq.rst b/docs/faq.rst index 5c8cd775f..94b784260 100644 --- a/docs/faq.rst +++ b/docs/faq.rst @@ -429,7 +429,7 @@ BORG_FILES_CACHE_TTL to at least 26 (or maybe even a small multiple of that), it would be much faster. Another possible reason is that files don't always have the same path, for -example if you mount a filesystem without stable mount points for each backup. +example if you mount a filesystem without stable mount points for each backup or if you are running the backup from a filesystem snapshot whose name is not stable. If the directory where you mount a filesystem is different every time, |project_name| assume they are different files. diff --git a/src/borg/archiver.py b/src/borg/archiver.py index 8ecba523f..d27074324 100644 --- a/src/borg/archiver.py +++ b/src/borg/archiver.py @@ -2122,6 +2122,11 @@ class Archiver: potentially decreases reliability of change detection, while avoiding always reading all files on these file systems. + The mount points of filesystems or filesystem snapshots should be the same for every + creation of a new archive to ensure fast operation. This is because the file cache that + is used to determine changed files quickly uses absolute filenames. + If this is not possible, consider creating a bind mount to a stable location. + See the output of the "borg help patterns" command for more help on exclude patterns. See the output of the "borg help placeholders" command for more help on placeholders.