Need better snapahot management? ZFS works on Linux :)

[chronoboy]

Tonight I have just compiled and am currently testing out ZFS on Linux through the fuse userland file system. So far, it looks promising and stable. Tomorrow I will be testing it out with VirtualBox VDIs to see if this is a solution to the somewhat limited snaphot/cloning options in VirtualBox.

If you would like to try out ZFS on your favorite Linux host today, it can be downloaded from this website: http://www.wizy.org/wiki/ZFS_on_FUSE

Enjoy! Tomorrow, I will be making another post in this thread regarding how well it functions and some examples on how to use it. Stay tuned!

PS. This would make perfect sense on why Sun is not jumping to branched snapshots, when their ZFS product can do it nicely. Unfortunately, at this time Windows hosts will not be-able to take advantage of ZFS. There is a version for MacOS X and I believe FreeBSD though.

[chronoboy]

Okay, as I have seen, using ZFS along side of VirtualBox has great benefits. The compression is very good, and there is little to no speed impact on the VM as I have seen thus far.

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Compression information:

Windows 2000 Uncompressed: 671M
Windows 2000 Compressed: 469M
Windows XP SP2 Uncompressed: 1.4G
Windows XP SP2 Compressed: 882G
Windows XP SP3 Uncompressed: 1.8G
Windows XP SP3 Compressed: 1.2G

You can fully use the images while they are transparently compressed in the VDI. The snapshot is also compressed.

Creating Linked-clones as seen in other VM products works like a charm in ZFS. You would create a clone in order to branch out the snapshot tree.

I would recommend ZFS to any VirtualBox power-user who needs a little extra. ZFS is very simple to use, with a very simple, but powerful command-set. For example, creating a ZFS file system is as simple as:

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zfs create zpool/WinXP

You can create a snapshot by using this simple command:

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zfs snapshot zpool/WinXP@today

Creating a linked clone is as simple as 1..2..3..

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zfs clone zpool/WinXP@today zpool/SW-Testing
VBoxManage internalcommands setvdiuuid /zpool/SW-Testing/WinXP.vdi

Basically, all the commands are in plain English. The man page is very informative and has examples to get even the most novice computer user started.

I have created a DEB package for my distro(Debian Etch), it may or may not work on Ubuntu, have not tested it there yet. If anyone would like a copy of this pre-compiled DEB, I can provide a link in this forum.

ZFS is truly the file system to end all file systems! Great job Sun, keep up the awesome innovation.

[cReslyn]

Thanks for sharing this.

[chronoboy]

Not a problem. I would also like to note, that using ZFS makes it easier to share VDIs among many users on your system.

For example, you would create a single pool of VDIs which would be used as templates for the users on the system. You would then create a Linked-clone using ZFS for each user, and provide them with ownership of the Linked-clone. Even though, the orignal is say, owned by a special user who admins VBox VDI templates. The users will have read-write access to their own Linked-clone, not even knowing it is not the original VDI. Here's some simple code to get you started:

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zfs create zpool/tpl
zfs set compression=on zpool/tpl
zfs create zpool/tpl/WinXP
zfs create zpool/tpl/Linux
...

chown -R vmadmin:vmadmin /zpool/tpl

After this done, create the VDIs inside each pool and configure them accordingly. After you have the systems set-up, here is the next part:

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zfs -r snapshot zpool/tpl@base
zfs clone zpool/tpl/WinXP@base zpool/user1
chown -R user1:user1 /zpool/user1

There is no need to change the UUID, as this VDI will be used by a different VBox on the same machine. The -r option for snapshot enabled recursive mode, this is very handy.

Well, that's it for this session. I'll keep adding new scenarios to this post on how ZFS can be used to enhance the VBox experience. If you have any questions on ZFS, feel free to ask and I'll answer it to the best of my knowledge and look-up the rest.

Enjoy!