Dan Bretherton
2012-Nov-05 12:19 UTC
[Gluster-users] Re. Is there a way to force a brick in a replica set to automatically self heal after it goes down and comes back up?
> On 10/24/2012 02:20 PM, Kushnir, Michael (NIH/NLM/LHC) [C] wrote: > >/ I am thinking of a scenario where a brick #2 in two-brick a replica set goes > />/ down and then comes back up. It will be inconsistent with brick #1. From what I > />/ understand, missing and changed files are not replicated until a user reads or > />/ writes to those files. Is there a way to make the brick auto-heal when it comes > />/ back up? > / > In 3.3 onward, there is a feature called "proactive self-heal" which will > automatically start repair in such cases. It's also more efficient than > relying on find|stat from a client, though the client driven self-heal is still > there as a belt-and-suspenders kind of thing.Am I right in thinking that self-heal is also supposed to take place when files are accessed by users? I found recently that this does not happen for files that users don't have write access to. Last week a user kept reporting lots of I/O errors on files in various directories, but every time I checked the files as root there were no errors. A lot of xattr errors had been caused by problems I reported in other threads, and I explained to the user that there was a self-heal process going on in the background. I also told him that if he encountered files that had not yet been healed, a self-heal would be triggered on demand. As the user became progressively more annoyed during the week I looked into it more carefully, and I realised that the self-heal was only being triggered when I tried to access the files as root, or as a user with write access to the files. Is this expected behaviour? It's certainly not what I expected or wanted. I healed the users' files using a GlusterFS 3.2 style find|stat, but that's not something I thought would be necessary in version 3.3. -Dan. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://supercolony.gluster.org/pipermail/gluster-users/attachments/20121105/bfb2acb1/attachment.html>