Talk:Ploop/Why

zfs zvol

Have you noticed that you are replicating the code of ZFS ZVols? All these features are available in ZVols and they work on Linux just fine, and they work *today*. (the talk page was inaccessible, sorry about this. Rudd-O)

—The preceding unsigned comment was added by 208.54.5.241 (talk • contribs) 03:45, 24 June 2012.

Well, I can see a few differences here:

1. zfs have a license that incompatible with the GPL v2 which covers the Linux kernel

2. zvol can only be run on top of zfs, ploop can support any fs (potentially)

3. ploop can work over NFS

4. zvol snapshot feature is in fact implemented in zfs, ploop snapshot is implemented in ploop

--Kir 13:04, 8 July 2012 (EDT)

Sorry but some this of this information about ZVOL are wrong or tendencious.

1. It's true, the ZFS (OpenZFS) yet not compatible with GPL and becouse of this don't come with the vanilla kernel. But the same can be said by OpenVZ code, even the code being compatible with GPL it is not accepted and implemented in vanilla version of the Kernel. So we still need to use modified versions of the Kernel to use all functions of OpenVZ, the same happens with the ZFS on Linux that we have to use a kmod to make it work. But this is even easier to implement and far more compatible than the OpenVZ itself.

2. ZVOL don't run over ZFS, ZVOL is a subvolume controller that run over their own infrastructure know as ZPOOL, ZFS is only the default file system that runs on top of a ZVOL and can be easily changed to any other. PLOOP theoretically can run any FS but still not implemented yet and still only runs over the ext4 only (even after 4 years and RHEL 7 that uses XFS as default).

3. PLOOP only works over old NFSv3, and not supports NFSv4 ([1]) but you can easily mount an external filesystem using NFSv4 with SIMFS.

4. ZVOL snapshot feature is implemented in ZVOL not in ZFS, you can easily make snapshots of any file system over it.