[mythtv-users] Some master/slave backend advise required

[Gary Buhrmaster]

On Tue, Jun 3, 2014 at 4:11 AM, Jean-Yves Avenard <jyavenard at gmail.com> wrote:
>
> and why would that be.

As I said, buffer & memory management.  ZFS (ARC) is tightly
integrated into the memory management functions of the OS.
ZFS is designed to have direct access to the disk.  The SPL
does not result in the same integration, simply providing another
layer on top of other Linux layers.  Yes, it works.  It does not
work as well as it does when integrated tightly into the OS.
There is even a fuse implementation for ZFS   It, too, works.

> ZFS on linux, from what I've experimented and put in production works
> extremely well. Just as well, if not sometimes better than the same
> plateform on FreeBSD

FreeBSD is not the reference platform (but its design makes
ZFS implementation more like Solaris)  It (too) has some porting
issues (as the bug lists for FreeBSD and ZFL report), and is
often in bug catch-up mode.

Solaris (closed source now) is the reference platform.  illumos
is (perhaps) considered the open source ZFS implementation upstream,
and Nexenta is (was?) where a lot of the (open) ZFS expertice is
currently employed.

In any case, while ZFS can work without tuning, the out
of the box experience will be poor for some workloads.

And back to the OPs config.  While learning ZFS is not a bad
thing, ZFS on Linux is never where one should start with their
MythTV box if one does not have extensive ZFS experience.
Too many new technologies will spoil the experience.