Support for ggated

[deed02392]

So ggate is a solution in FreeBSD which enables you to get local 'pseudo' devices of disks that are installed in other machines on a network.

I would love to have the benefits of ZFS RAID-Z2 for a collection of commodity servers. It seems to be taking from the content of this thread: http://forums.freebsd.org/showpost.php?p=214279&postcount=2

There is no support for any type of clustering in ZFS at all so you can't spread a pool across multiple servers.

We have, however previously discussed the usage of ggated to make disks on multiple systems available to one master/head server. ggate is a GEOM provider with a fairly straightforward idea - it provides a GEOM/disk device to Machine1 where all disk commands are sent over the network to Machine2 where the ggated service receives them and passes them down to the disk.

I'm not sure how far the person who was asking got with it. The idea is to expose the disks on all the servers but one (the highest specced one ideally) via ggated. You then mount those disks on the master/head unit and build a ZFS pool out of them. As ggate is sending raw GEOM commands across the network it should have fairly low overhead (I would suggest a decent low-latency GigE network or better, with server class interfaces if possible).

As an added bonus, ZFS will allow you to add local drives in the master unit as ZIL/cache devices.

NFS is built into the FreeBSD kernel, and as such has been linked into the ZFS commands. With the NFS server enabled in /etc/rc.conf you can share ZFS filesystems over NFS by just running

# zfs set sharenfs="-network=1.2.3.4/24" pool/filesystem

For CIFS you will need to install and configure net/samba36 as there is no built-in support for it. This also means you can't use the sharesmb properties in ZFS.

... that something like this is possible using ggated, and then forming a pool across all the remote disks (because you can expose them locally as devices), but obviously this is only going to work if FreeNAS can work with these devices. Does anyone know if they are mounted/exposed in such a way FreeNAS can work directly with them?

For now it may be that we have to setup ggatec on the FreeNAS server manually, mount all the disks and then set up FreeNAS to build a pool on all these devices. But if that's actually possible, surely this is something FreeNAS could provide built-in, thus making FreeNAS effectively a clustered NAS storage solution (SAN?).

Thanks for your time.