On Wed, Mar 18, 2015 at 6:22 PM, Rumen Telbizov <[email protected]> wrote:
> > > *Can I directly access the data on the underlying storage volumes?* >> >> If you are just doing just read()/access()/stat() like operations, you >> should be fine. If you are not using any new features (like >> quota/geo-replication etc etc) then technically, you can modify (but surely >> not rename(2) and link(2)) the data inside. >> >> Note that this is not tested as part of gluster’s release cycle and not >> recommended for production use. >> > > The last sentence doesn't recommend it for production use. I was wondering > if there's any other concern besides the fact that it's not tested as part > of the release cycle or one could expect actual some problems with the data > being read while doing so? > > What I am interested is *only* read operations (readdir, stat, read > data). All the write operations will continue going over the shared/mounted > drive. So what I want to know is that the data that I am reading will be > consistent with the rest of the bricks and not corrupted in any way. > This is not necessarily a direct answer to your question but I've tested something similar. With a running volume (but not mounted anywhere), I copied a file directly to the underlying FS directory (a tarball) to test how it would react if a client would mount the volume afterwards. When a client mounted the Gluster filesystem (FUSE client), after some time, the tarball I copied on one of the bricks was replicated to the other servers in my 3 replica test environment. I tested the tarball on each gluster server and it was perfectly consistent. During all my other tests, I did things like the one you intend to do. Mounted the gluster volume on a client and copied some big files there. While the copy was doing its job, I directly accessed the resulting file on the servers to see if it was consistent (checking the first few KB of the file to check headers) I haven't found anything to complain about and all seemed consistent to me so I'd say that what you plan to do is fairly safe. -- Unix _IS_ user friendly, it's just selective about who its friends are.
_______________________________________________ Gluster-users mailing list [email protected] http://www.gluster.org/mailman/listinfo/gluster-users
