9 Alternatives for Windows Home Server’s Drive Extender
http://www.howtogeek.com/howto/36458/9-alternatives-for-windows-home-servers-drive-extender/
greyhole vs zfs
Ceph is a distributed object store and file system designed to provide excellent performance, reliability and scalability.
GlusterFS is a powerful network/cluster filesystem written in user space which uses FUSE to hook itself with VFS layer. GlusterFS takes a layered approach to the file system, where features are added/removed as per the requirement. Though GlusterFS is a File System, it uses already tried and tested disk file systems like ext3, ext4, xfs, etc. to store the data. It can easily scale up to petabytes of storage which is available to user under a single mount point.
MooseFS – MooseFS is a bit more involved than the other solutions but it is much more flexible as well. All of the other solutions have relied on one machine with a lot of hard drives plugged in. MooseFS relies on a couple servers running management with a lot of other computers doing the storage. It is called a distributed filesystem and if you have Linux computers lying around your house this may be your best solution. Otherwise it probably is best to leave it for corporations and businesses.