Access a ZFS volume in Windows?

Question

You'd think this would have been asked but I can't seem to find it so...

Let's say I have a ZFS setup in this enclosure (8 bay USB3 JBOD):
https://web.archive.org/web/20111018042134/http://www.sansdigital.com/towerraid-/tr8uplusb.html

Now, I'm going to be running it on my Mac direct attached but I'd like to be able to access the files when I boot into Windows as well. With HFS+ volumes Apple was kind enough to provide a means for doing this. However, I can't find one for ZFS.

The only solution I've come across is using Open Solaris in a Virtual Machine to mount the drives. However, I've also heard more than a few nightmares about doing this and it leading to massive failures... Yeah, kind of the exact opposite of what I want.

So, essentially, what is the current best means of accessing a ZFS volume attached to Windows? I'd be happy with read-only access if necessary.

Oh, intended OS is Windows 7.

Answer 1

There is no OS level support for ZFS in Windows.

As other posters have said, your best bet is to use a ZFS aware OS in a VM.

Options are:

• Open Solaris
• FreeBSD
• Linux (through zfs-fuse, or zfs-on-linux)

One other possibility is to get hold of a small low-powered computer (say an Atom based system) to connect to the drives and act as a network head unit to the disks sharing the data out through the network through a standard protocol like CIFS (Samba). Then you can run the ZFS aware OS direct on the metal.

Answer 2

zfs-win

• https://github.com/dominicusin/zfs-win (automatically exported from https://code.google.com/archive/p/zfs-win/ – thanks to Tiberiu-Ionuț Stan for the hint)
• GNU GPL v2
• requires Dokan

… read-only drive can be mounted …

— and I guess that further development might enable write access.

Following installation on Windows 7:

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\Users\Administrator>chdir "C:\Program Files (x86)"

c:\Program Files (x86)>zfs-win
ZFS for Windows

usage:
  mount <mountpoint> <dataset> <pool ..>
  list <pool ..>

examples:
  zfs-win.exe mount "m:\" "rpool/ROOT/opensolaris" "\\.\PhysicalDrive1" "\\.\PhysicalDrive2"
  zfs-win.exe list "Virtual Machine-flat.vmdk"

Whilst editing the compatibility section of the OpenZFS wiki I was advised that zfs-win can not read ZFS pool version 28. (I don't do code, so from the source I can't tell which version is supported – sorry.)

Answer 3

ZFS in virtual machine can work just fine if follow one simple rule never ever lie to ZFS. ZFS goes to great length to keep your data from getting corrupted (checksums, copy-on-write, dittoblocks, mirrors or raid-z, etc) so you should do everything in your power to let ZFS directly access your disks. All the horror stories of virtualized ZFS issues come from some level of buffered IO from virtualization software buffers, disk controller cache or even windows with writethrough cache if you're dumb enough to use virtual disks instead of whole raw disks. Each virtualization package does raw disks slightly differently, but VMWare Workstation, VMWare Fusion and VirtualBox all support it without too much effort.

You mentioned attaching it to your Mac, so you could either use something OSX native like ZEVO (formerly Z-410) or run a ZFS virtual machine just like you would from Windows 7. If your moving your pool between mac/windows (ZEVO <-> VM) you'll want to zpool export poolname before switching. No need if your booting the same VM on both sides. You should strive to have no virtual disks (vmdk files) hosted on HFS+ or NTFS but instead make one of the external disks (or an partition of your internal disk) bootable so you can boot it non-virtually without too much effort.

Of note if your Mac has Thunderbolt you can use that instead of USB2 or FireWire to connect multiple disks for ZFS. Something like a SonnetTech Thunderbolt PCIe bridge (ExpressCard or PCIe) combined with an eSATA or SAS card (or even a USB3 card) will be orders of magnitudes faster than regular USB2.

Answer 4

There's now (2017) a native ZFS implementation for Windows (10 only?) available at:

https://github.com/lundman/zfsin

The discussion here indicates that it's a high-quality port:

https://news.ycombinator.com/item?id=15549190

Answer 5

I'll bet by the age of this thread that you've already moved on, but I'll put my two cents in for the sake of anyone else who still has questions on this matter.

I have built several NAS machines using ZFS as the file system. One of the easiest to use is either FreeNAS or NAS4Free. I've also used Solaris before the previous two offered de-duplication and encryption in their ZFS release versions. As was mentioned, you can use the Atom processors with success as a low power motherboard solution. Just be sure to feed them as much RAM as the board can support to make up for the lack of power from the CPU. Obviously, a NAS isn't quite as fast as a local disk, but it's better than not reaping the benefits of ZFS at all.

I've used a VM to access some USB sticks that I in turn formatted with ZFS in a RaidZ pool. I then shared them tho the host machine through a virtualized LAN connection. While it did work, I don't know what kind of reliability or performance issues you would be up against doing something like that. USB drives are so inherently slow that no worthwhile data would have been obtainable from that setup... so, I never bothered to test it. However, I imagine there would be a lot of CPU overhead doing something like that.

In all, if you have the budget, I would suggest doing a NAS over a VM. Last month I built one with a small Chenbro case and a Supermicro Atom board. I fed it 4GB of RAM and 4x3TB SATA drives in RaidZ. It bench-marked at 135MBps sustained. I've not performed any other tests.

Answer 6

Using a ZFS aware OS in a virtual machine is your best bet. ZFS is pretty robust and supports importing and exporting pools form different OSes so there should be no massive failures or nightmares doing it.

Answer 7

I have completely reliable zfs read write access in windows 7. Windows 7 thinks it is an NTFS share over SMB. Here's how. The NAS is an Ubuntu 13.04, with native zfs installed. Not fuse, via the ubuntu-zfs metapackage, which installs 0.6.1-1~raring package. This is running on a 32 bit old desktop computer resuscitated out of an old closet. 1 gig of ram, soon to be upgraded to 2gb. MSI 845-G Max motherboard. Attached to this is an 8 drive Sansdigital box, connected via portmultiplier. In there is 4 3 TB barracuda drives. And a 120 GB Vertex 3 SSD as a cache and a log. I created a zpool of raidz2 of the 4 disks, plus the cache and log. Then I executed :zfs set sharenfs=on 'zpoolname' This gives a mild error that the share may or may not work. THen I create folder inside my zpool in the "computer" device of root nautilus. Then I share the folder. Voila .....

A network accessible zfs inside windows 7, which reports it as NTFS. I can do a "map network drive" in windows 7, and I now have a 10 terabyte ntfs drive in windows 7. Obviously it is not bootable. And it is only as reliable as all of the hardware it is composed of. But, I have dedup on, compression on, and it should survive a loss of 1 or 2 of my 3 Terabyte drives.

I hope this works for someone else.

Answer 8

Aparrently there is a commercial tool claiming read support for 'Sun ZFS'...

http://www.ufsexplorer.com/download_stdr.php

"as well as access to files on Sun ZFS,"

Not sure how good it is / haven't tried it yet.

Answer 9

I don't think it's possible at the moment. I haven't found ZFS drivers for Windows, but the code is open-source so it should be possible to write one.

Answer 10

I've recently tested this on my Gentoo desktop at work. Create a zvol on a *nix of your choice, format it to NTFS and share via samba. Active Directory permissions work fine, the only slight annoyance is samba has to be stopped to rollback a snapshot, but that's not really a big deal as it can be done in seconds. My plan is to create a live copy of all my users data and snapshot it daily. More as a means of reclaiming accidently deleted files than a true backup. Now I just need to talk them into letting me buy another server.