mirror
/
borg
mirror of https://github.com/borgbackup/borg.git
1
0
Fork 0
Code Issues Releases Wiki Activity

docs: internals: amend feature flags

This commit is contained in:
Marian Beermann 2017-06-05 00:21:04 +02:00
parent f2fd6fc699
commit c427d238f4
1 changed files with 13 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
docs/internals/data-structures.rst
View File

@ -310,7 +310,7 @@ or modified. It looks like this:
b'item_keys': [b'acl_access', b'acl_default', ...],
b'config': {},
b'archives': {
b'archive name': {
b'2017-05-05-system-backup': {
b'id': b'<32 byte binary object ID>',
b'time': b'2017-05-05T12:42:22.942864',
},
@ -392,6 +392,10 @@ These can be locked out with manifest version 2. Thus, the only difference betwe
manifest versions 1 and 2 is that the latter is only accepted by Borg releases
implementing feature flags.
Therefore, as soon as any mandatory feature flag is enabled in a repository,
the manifest version must be switched to version 2 in order to lock out all
Borg releases unaware of feature flags.
.. rubric:: Cache feature flags
`The cache`_ does not have its separate flag of feature flags. Instead, Borg stores
@ -414,13 +418,18 @@ relevant to operating the cache. Otherwise, the client would not pass the featur
set test against the manifest.
When opening a cache and the *mandatory_features* set is a superset of the features
supported by the client, the cache is wiped out and rebuilt.
Since a client not supporting a mandatory feature that the cache was built with
supported by the client, the cache is wiped out and rebuilt,
since a client not supporting a mandatory feature that the cache was built with
would be unable to update it correctly.
When opening a cache and the intersection of *ignored_features* and the features
supported by the client contains any elements, i.e. the client possesses features
that the previous client did not have, the cache is wiped out and rebuilt.
that the previous client did not have and those new features are enabled in the repository,
the cache is wiped out and rebuilt.
While the former condition likely requires no tweaks, the latter condition is formulated
in an especially conservative way to play it safe. It seems likely that specific features
might be exempted from the latter condition.
.. rubric:: Defined feature flags