distributed fs: add source code links

- ref. https://github.com/awesome-foss/awesome-sysadmin/issues/416

README.md

@@ -314,22 +314,22 @@ _See also: [awesome-selfhosted/Database Management](https://github.com/awesome-s
 
 *Network distributed filesystems.*
 
-- [Ceph](https://ceph.com/) - Distributed object store and file system.
-- [DRBD](https://linbit.com/drbd/) - Distributed Replicated Block Device.
-- [GlusterFS](https://www.gluster.org/) - Scale-out network-attached storage file system.
+- [Ceph](https://ceph.com/) - Distributed object store and file system. ([Source Code](https://github.com/ceph/ceph))
+- [DRBD](https://linbit.com/drbd/) - Distributed Replicated Block Device. ([Source Code](https://github.com/LINBIT/drbd))
+- [GlusterFS](https://www.gluster.org/) - Scale-out network-attached storage file system. ([Source Code](https://github.com/gluster/glusterfs))
 - [Kubo](https://github.com/ipfs/kubo) - Implementation of [IPFS](http://ipfs.io/), a global, versioned, peer-to-peer filesystem that seeks to connect all computing devices with the same system of files.
-- [Hadoop Distributed Filesystem (HDFS)](https://hadoop.apache.org/) - Distributed, scalable, and portable file-system written in Java for the Hadoop framework.
+- [Hadoop Distributed Filesystem (HDFS)](https://hadoop.apache.org/) - Distributed, scalable, and portable file-system written in Java for the Hadoop framework. ([Source Code](https://github.com/apache/hadoop))
 - [JuiceFS](https://juicefs.com/) - Distributed POSIX file system built on top of Redis and S3. ([Source Code](https://github.com/juicedata/juicefs)) `Apache-2.0` `Go`
-- [LeoFS](https://leo-project.net) - Unstructured object/data storage and a highly available, distributed, eventually consistent storage system.
-- [Lustre](https://www.lustre.org/) - Parallel distributed file system, generally used for large-scale cluster computing.
+- [LeoFS](https://leo-project.net) - Unstructured object/data storage and a highly available, distributed, eventually consistent storage system. ([Source Code](https://github.com/leo-project/leofs))
+- [Lustre](https://www.lustre.org/) - Parallel distributed file system, generally used for large-scale cluster computing. ([Source Code](https://git.whamcloud.com/?p=fs/lustre-release.git;a=summary))
 - [Minio](https://min.io/) - Minio is an open source object storage server compatible with Amazon S3 APIs. ([Source Code](https://github.com/minio/minio)) `AGPL-3.0` `Go`
-- [MooseFS](https://moosefs.com/) - Fault tolerant, network distributed file system.
-- [OpenAFS](https://www.openafs.org/) - Distributed network file system with read-only replicas and multi-OS support.
-- [Perkeep](https://perkeep.org/) (née Camlistore) - A set of open source formats, protocols, and software for modeling, storing, searching, sharing and synchronizing data.
-- [SheepDog](https://sheepdog.github.io/sheepdog/) - A distributed Blockdevice, Rest, QEMU and distributed Filesystem storage.
-- [Swift](https://docs.openstack.org/developer/swift/) - A highly available, distributed, eventually consistent object/blob store.
-- [TahoeLAFS](https://tahoe-lafs.org/trac/tahoe-lafs) - secure, decentralized, fault-tolerant, peer-to-peer distributed data store and distributed file system.
-- [XtreemFS](https://www.xtreemfs.org/) - XtreemFS is a fault-tolerant distributed file system for all storage needs.
+- [MooseFS](https://moosefs.com/) - Fault tolerant, network distributed file system. ([Source Code](https://github.com/moosefs/moosefs))
+- [OpenAFS](https://www.openafs.org/) - Distributed network file system with read-only replicas and multi-OS support. ([Source Code](https://git.openafs.org/?p=openafs.git;a=summary))
+- [Perkeep](https://perkeep.org/) - A set of open source formats, protocols, and software for modeling, storing, searching, sharing and synchronizing data (previously Camlistore). ([Source Code](https://github.com/perkeep/perkeep))
+- [SheepDog](https://sheepdog.github.io/sheepdog/) - A distributed Blockdevice, Rest, QEMU and distributed Filesystem storage. ([Source Code](https://github.com/sheepdog/sheepdog))
+- [Openstack Swift](https://docs.openstack.org/developer/swift/) - A highly available, distributed, eventually consistent object/blob store. ([Source Code](https://opendev.org/openstack/swift))
+- [TahoeLAFS](https://tahoe-lafs.org/trac/tahoe-lafs) - secure, decentralized, fault-tolerant, peer-to-peer distributed data store and distributed file system. ([Source Code](https://github.com/tahoe-lafs/tahoe-lafs))
+- [XtreemFS](https://www.xtreemfs.org/) - XtreemFS is a fault-tolerant distributed file system for all storage needs. ([Source Code](https://github.com/xtreemfs/xtreemfs))
 
 
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