Help- I have multiple gluster filesystems, all with the setting: cluster.min-free-disk: 500GB. My understanding is that this setting should stop new writes to a brick with less than 500GB of free space. But that existing files might expand, which is why I went with a high number like 500GB. But I am still getting full bricks, frequently it's the first brick in the cluster that suddenly fills up. Can someone tell me how gluster chooses where to write a file. And why the min-free-disk is being ignored. Running 3.3.1 currently on all servers. Thanks, -Tom
On 04/15/2013 06:35 PM, Thomas Wakefield wrote:> Help- > > I have multiple gluster filesystems, all with the setting: cluster.min-free-disk: 500GB. My understanding is that this setting should stop new writes to a brick with less than 500GB of free space. But that existing files might expand, which is why I went with a high number like 500GB. But I am still getting full bricks, frequently it's the first brick in the cluster that suddenly fills up. > > Can someone tell me how gluster chooses where to write a file. And why the min-free-disk is being ignored. > > Running 3.3.1 currently on all servers. > > Thanks, > -Tom > _______________________________________________ > Gluster-users mailing list > Gluster-users at gluster.org > http://supercolony.gluster.org/mailman/listinfo/gluster-usersMake sure you are running 3.3.1 also on all the clients also. It is determined by the clients. I noticed there is a fix there is in 3.3.1 which is not in 3.3.0. In 3.3.0, it will try writing to the next brick which is the 1st brick, but only check if it is not 100% (completely) free. If it has 1 byte left, it will start writing to it, and that's why the 1st brick will get filled up. ... ling
On 04/15/2013 06:35 PM, Thomas Wakefield wrote:> Help- > > I have multiple gluster filesystems, all with the setting: cluster.min-free-disk: 500GB. My understanding is that this setting should stop new writes to a brick with less than 500GB of free space. But that existing files might expand, which is why I went with a high number like 500GB. But I am still getting full bricks, frequently it's the first brick in the cluster that suddenly fills up. > > Can someone tell me how gluster chooses where to write a file. And why the min-free-disk is being ignored. > > Running 3.3.1 currently on all servers. > > Thanks, > -Tom >Except for the full-brick allocation, which I haven't read the source to figure out, here's a general answer to your question about how the client chooses where to place a file: http://joejulian.name/blog/dht-misses-are-expensive/