Hi Kunal,

Glad to hear that you could come up with a working GlusterFS setup. I’ll try to answer your questions as far as I can.

1. I have to admit that I never had any experience with embedded applications. All I can say is that GlusterFS is a clean and simple POSIX-compatible userspace file system. In that regard, I have seen articles describing GlusterFS configured with Raspberry Pi and so on. I hope that helps to look for possible developments in the embedded world.

2. To the best of my knowledge there is no server-side replication happening in GlusterFS. Everything is on the fly as in modifications or updates should happen simultaneously to replica sets.

Therefore it boils down to how effectively file access is maintained using locks or similar mechanisms to avoid data corruption. Because in the best-case scenario you don’t need to worry about any replication happening while files are being accessed by clients.

3. QEMU integration is something I can tell from the top of my mind. I’m sure you will be able to find articles(old) from gluster.org explaining the architecture behind the use case. I’m adding one such link which I could get hold of quickly. Otherwise media backup/archival is also an area where GlusterFS deployments are common. Also, see the second link with references to different use cases.

* https://www.gluster.org/qemu-glusterfs-native-integration/
* https://www.gluster.org/category/use-case/

4. “smallfile” [https://github.com/distributed-system-analysis/smallfile] is a great tool for benchmarking POSIX-like filesystems. For a quick check, you may also look at periodic performance reports (search for keyword ‘report’) sent to the Gluster Devel mailing list covering various workloads like smallfile, large files etc.

I have also created a volume and mounted using VM.

Created files from different nodes and could access them.

Few questions:
1- Is GFS suitable for embedded applications?
2- Is the file accessible while it is under replication?
3- Where can we get different characteristics or use cases of GFS?
4- How to check performance and load calculation ?

The whole logic of file distribution and replication resides on the client side stack of GlusterFS. For example, client will perform a write operation to both servers in a replica set of 2 . There is no communication between the servers(or bricks in terms of GlusterFS) themselves.

But with GlusterFS 4.0, overall structure is intended to change which also includes the concept of server-side replication termed as JBR(Journal Based Replication). More details on JBR can be found at Red Hat – Next Generation File Replication system in Gluster FS

Stay tuned to GlusterFS mailing lists for more updates or jump into #gluster on Freenode IRC.