Conceptually, and I don't think I am alone here, I love the concepts of ZFS. You can create one big disk, everything is stored on multiple drives, and you can grow and shrink the pool and drive at any time. Plus, the disks don't need to be same etc.
What I hate about ZFS is that, best I can tell, its only truly stable form on Solaris running on Oracle (formerly Sun) hardware. Sure, OpenSolaris exists, and FreeBSD has ZFS support, but reliability is generally said to be poor when on FreeBSD/OpenSolairs/Solaris on non oracle hardware.
We run (exclusively at the moment) Window Server 2008 R2 servers. What is the "next best" DAS storage option for this OS? I can't find a ZFS implementation for windows, so that's out. There are a myrad of RAID cards out there: can someone recommend a setup that approaches ZFS flexibility? A setup where you can just add a disk to the pool and bam more storage without having to take the server down for rebuild?
In Sum: if you love ZFS but want to run Windows Server 2008 R2 whats your best/coolest option(s)?
PS: This is for in production systems, budget is on the order of 10k per system.
As far as I know, really the only option you have that approaches being somewhat reliable is to get a SAN that implements storage virtualization and connect your windows servers to it via iSCSI/FC/FCoE/etc.
The SAN will be able to give you similar features as ZFS does: snapshots, dynamic volume sizing, cloning, etc.
Like others are saying there is nothing comparable to ZFS on Windows, so if you want to use ZFS it will have to be attached through the network in some form.
If you check the compatibility of the hardware carefully you should also have no problems running it on non-Oracle hardware, in my (albeit limited) experience. From what I gather the most important things to look out for are:
I would recommend a Solaris-based OS over FreeBSD or Linux for performance and stability reasons, or if you need any of the features only recent ZFS versions support (like encryption). That means your OS options are Solaris 10, Solaris 11 Express, or one of the forks of OpenSolaris. Nexenta Core (or the more appliance-like NexentaStor), OpenIndiana and Schillix seem to be the most prominent. If you decide on an Oracle-supported OS the license costs are currently $1000 / socket for non-Oracle x86 hardware.
I'm currently running a test file server on ZFS. If your requirements are similar to ours you might get by without going the iSCSI route and instead using Solaris built-in CIFS support to make ZFS file systems appear as regular Windows shares. It was relatively easy integrating it with Active Directory for athentication, and it's been a lot less pain than Samba so far.
If you need the storage to appear as a native Windows drive - for a database, for instance - iSCSI is your only option. Beware that you then lose the ability to grow the drive easily as you need to dedicate a set amount of ZFS pool space to the iSCSI share. If you need iSCSI I would advise you to get a beefier network setup than the single gigabit card suggested above - we had no problems saturating a gigabit connection with just four old 5400 RPM desktop drives in RAIDZ on a 1.5 gbit HBA. A 10-gigabit card or at least a four-port gigabit card with link aggregation would be better.
I think you have some of the concepts of ZFS wrong. You can't actually shrink pools, however it is possible to create and delete filesystems and such on the fly using pooled storage. Honestly, short of using a ZFS-based solution, I think HP's Smart Array controller solution is extremely clean and allows flexibility with its logical drives. Let's say you have 8 disks. Within that array, you can have smaller logical drives that can use differing RAID levels. They can also be expanded easily. So that's something that's unique to HP ProLiant servers, but is a good alternative in a Windows environment.
As far as ZFS is concerned, you can buy a canned ZFS solution from several vendors. Take a look at NexentaStor as well as PogoLinux, who sells packaged and preconfigured NexentaStor systems on certified hardware. These solutions would definitely fit within your budget.
Personally, I use NexentaStor for my ZFS deployments, but went the route of tailoring HP ProLiant hardware for the task since that's what I'm most familiar with. Either way, there's no requirement to run on Oracle hardware to attain stability in ZFS.
There is a couple of options you can look forward in windows. Windows ntfs file system has supports for logical disk management. You can read more and see if it fits your requirement from http://technet.microsoft.com/en-us/library/cc758035(WS.10).aspx. The other option you have is to use veritas volume manager http://www.symantec.com/business/storage-foundation-for-windows .
Set up an Illumos/OpenSolaris system as a SAN and use iSCSI on the Windows server to attach to disk volumes on the SAN. Set it up so that the Windows server has an extra gigE card attached to a gigE switch which the server is attached to so that the iSCSI traffic basically has its own dedicated switch.
To backup something like SQL Server, shutdown SQL server, tell the Illumos machine to snapshot the ZFS volume where the db is stored, restart SQL server and then use ZFS send/recieve to backup the snapshot to another server. Doing it this way means that you can backup your databases with very minimal downtime.
I understand that this question is pretty much obsolete now since we have Storage Spaces already. Now the problem isn't flexibility, it's performance. Just look at the charts:
Storage Spaces vs. ZFS
ZFS, and more specifically, RAID-Z annihilates pretty much eveything else out there. Please vote for the ZFS on Windows Server idea on UserVoice (linked on the bottom of the article), thanks!