diff options
| author | Lars Wirzenius <liw@liw.fi> | 2014-02-11 19:43:03 +0000 |
|---|---|---|
| committer | Lars Wirzenius <liw@liw.fi> | 2014-02-11 19:43:03 +0000 |
| commit | 28ace2b1573537bf6d980e5acd210d0b409b0c86 (patch) | |
| tree | 96eb454727cfe2726a4908a261c81b06fe917501 /manual | |
| parent | 4f2be4e84ca063e19b8bdcae803df54ca4a44886 (diff) | |
| download | obnam-28ace2b1573537bf6d980e5acd210d0b409b0c86.tar.gz | |
Add section on dealing with locks during backups
Diffstat (limited to 'manual')
| -rw-r--r-- | manual/060-backing-up.mdwn | 37 |
1 files changed, 34 insertions, 3 deletions
diff --git a/manual/060-backing-up.mdwn b/manual/060-backing-up.mdwn index 9df75cda..95125c87 100644 --- a/manual/060-backing-up.mdwn +++ b/manual/060-backing-up.mdwn @@ -304,9 +304,40 @@ slow, then the comparison will take significant time. Locking ------- -This section discusses Obnam's approach to locking parts of the -repository during backups, and what to do if the backup process -crashes and leaves lock files around. +Multiple clients can share a repository, and to prevent them from +trampling on each other, they lock parts of the repository while +working. The "Sharing a repository between multiple clients" chapter +will discuss this in more detail. + +If Obnam terminates abruptly, even if there's only one evern client +using the repository, the lock may stay around and prevent that one +client for making new backups. The termination may be due to the +network connection breaking, or due to a bug in Obnam. It can also +happen if Obnam is interrupted by the user before it's finished. + +The Obnam command `force-lock` deals with this situation. It is +dangerous, though. If you force open a lock that is in active use by +a running Obnam instance, there will likely to be some stepping of +toes. The result may, in extreme cases, even result in repository +corruption. So be careful. + +If you've decided you can safely do it, this is an example of how to +do it: + + obnam -r /media/backups/tomjon-repo force-lock + +Note that some of the locks are per-client, to prevent you from +accidentally running Obnam twice for the same client, which would +result in standing on your own toes: kind of impressive, but +uncomfortable and not recommended. + +If you need to force open a lock for specific client, you can specify +the client name explicitly: + + obnam --client-name magrat \ + -r /media/backups/tomjon-repo force-lock + +(Long line broken to two for typographical reasons.) Consistency of live data ------------------------ |