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ZFS is awesome. I never would have imagined I could ever get excited about a filesystem, but I did. If you've never used it, I encourage everyone to check it out. It's so completely "flexible" and you can do things that you never would've thought of.

A while back, my personal mail server ran on FreeBSD 9.x on bare metal. I wanted to rebuild the physical host but run everything in jails on a "clean" 10.x install instead. I created a new virtual machine on our ESXi cluster, booted it with an mfsbsd image, and prep'd the hard disks. Back on the server, I shut down all the services, took snapshots, and shipped them off to the VM using ZFS send/receive. In short order, I had P2V'd my mail server and it worked wonderfully. I left everything running in that VM for a few days while I rebuilt the physical server and got all of my jails set up and then moved it all back.

Allan Jude gave a cool talk at vBSDcon a few months ago entitled "Interesting Things You Didn't Know You Could Do With ZFS" [0]. If you've never used ZFS or you're wondering what it might have over your current filesystem of choice, you might check it out.

[0]: https://www.youtube.com/watch?v=qXOZmDoy2Co

⬐ tropin

Can you have your / in linux in zfs?

⬐ amyjess

Yes, I did that on my desktop, running Arch Linux.

In retrospect, it probably wasn't a very good idea because my / is on an SSD and ZFS on Linux doesn't support TRIM (I'll probably go with XFS if I ever reinstall), but it's totally doable.

⬐ lars512

Sure, if your /boot is something else.

⬐ 4ad

Not required, some versions of Grub can read from ZFS just fine.

⬐ josteink

Ubuntu 16.04 should come with "official" ZFS from Ubuntu[1].

Hopefully this means everything, including booting from ZFS, should work out of the box.

[1] http://www.phoronix.com/scan.php?page=news_item&px=Ubuntu-ZF...

⬐ mrbig4545

The one thing I know how to do really well with ZFS is get confused by the extended ACLs!

⬐ sanjaynegi89

really cool

⬐ markild

Things you can't do with ZFS:

- Use it together with GPL-licensed software

⬐ oskarth

Your comment would be more honest if it started with "Things you can't do with GPL".

⬐ None

None

⬐ throwaway7767

The thing I miss most in ZFS (aside from a native in-kernel linux port, as I've found ZoL to be kinda buggy) is to be able to grow zdevs. I can add a new zdev, I can remove them, but I can't add one disk to my 7-disk RAIDZ2. MD RAID has no problem with this.

Also, if you add zdevs later, you will never get full performance again as the striping will be off (putting more writes on the zdevs with more free space), and there's no 'rebalance' kind of thing (I've seen some scripts that just move stuff around, but I've never seen any evidence that they work, and I really doubt that they do based on my understanding of zdev allocation).

⬐ Scramblejams

Me too. I've added so many drives in onesies and twosies to so many MD RAID5/6 arrays over the years that I simply can't confidently deploy ZFS for that case.

⬐ cmurf

md RAID will require a lengthy reshape. BTRFS supports adding a new drive, reshape (balance) is optional.

⬐ throwaway7767

> md RAID will require a lengthy reshape

Array reshapes are rare, and it'll only use idle IO bandwidth anyway. Redundancy is guaranteed during the whole process. So I don't see this as a problem.

> BTRFS supports adding a new drive, reshape (balance) is optional

Thanks for pointing this out. I didn't know btrfs supported array reshapes. I'm waiting for it to mature (RAID5/6 was only added in 3.19, for example) but I expect I'll switch over at some point, probably at the point it's considered "boring" (exactly the experience I want from my filesystems).

⬐ nathan7

I'm assuming you mean vdevs — you can resize zvols (virtual block devices) just fine. (and you can even grow disk-type vdevs, though they'll be somewhat unbalanced)

⬐ throwaway7767

Yeah, sorry, edited. It's mainly the ability to resize RAIDZ or RAIDZ2 zdevs that would be really helpful.

⬐ moviuro

You can. ZOL does that.

Blame the GPL plague-like principle.

⬐ baq

blame Sun and Oracle for releasing it under a license designed to be incompatible with GPL.

⬐ bestham

According to Bryan Cantrill that is not at all accurate https://youtu.be/-zRN7XLCRhc?t=1364

* Edited for wrong link

⬐ baldfat

Listen to it and the whole point he is making is we had to make way for proprietary drivers and not to block it being compatible with GPL.

Seem very much a grammar Judo to say we didn't go out of the way to be anti-compatible with GPL but we invented a copy left license so we could never be compatible with GPL.

⬐ bestham

Well how much work can you expect a for-profit-company to do in order to release their software as open source? They choose a licence that worked for them, then and there because of reasons. This included the work on ZFS.

There are operating systems that have licences that permit the ZFS code in the kernel. What reasons did SUN have to specifically block the Linux kernel but not BSD / Darwin ? The choice of license has everything to do whit what license SUN was comfortable using and nothing to do with keeping GNU/Linux out of the party.

If the answer is that a lot of their competitors at the time were invested in GNU/Linux and thus could not use their code, that is a very short sighted move.

⬐ baldfat

> Well how much work can you expect a for-profit-company to do in order to release their software as open source?

A lot actually I expect them to make open source software and in all regards this has happened.

http://www.infoworld.com/article/2914643/open-source-softwar...

⬐ Fedjmike

Couldn't they have dual licensed it under both the CDDL and GPL? CDDL for when they distribute it with the closed drivers, then additionally distribute the source under the GPL allowing it to be used in Linux.

⬐ protomyth

Probably not, since that would have allowed someone to add GPL-only code to it which couldn't be distributed with the whole.

The video is very good and you can follow-up with https://www.youtube.com/watch?v=l6XQUciI-Sc

⬐ yrro

I don't understand; Sun would not have been obligated to accept contributions that were not similarly dual-licensed...

⬐ protomyth

The same theory as the GPL, why allow people to use your work if you cannot use their additions in return?

⬐ csirac2

Both are to blame. Neither are to blame. Much of the success of Linux has been attributed to the GPL. It certainly had a role to play in opening up WRT firmware.

The truth is that the GPL is a pretty restrictive license. I don't think it's fair to blame anyone for the fact that it's not compatible with much. That's its defining feature and the main reason people choose it; so if it blocks ZoL, it's working as intended.

Which I consider a great loss. ZFS is fantastic.

I use the BSD 2-clause license on my own stuff, but I can think of situations where I'd rather use GPL.

⬐ masklinn

> Much of the success of Linux has been attributed to the GPL.

That I know, much of the success of Linux has been attributed to GNU, and mostly in the sense that it made Linux's legal background very clear while BSD's libc was in legal limbo (Linux used glibc which had been funded by the FSF for the express purpose of having a clearly free software libc)

⬐ baldfat

There seems to be a ton of commercial and proprietary software and services on Linux with the GPL. Too many people just don't understand the GPL.

If you make changes you must share the changes does not equal Plague Like.

GPL is the most used and misunderstood license. It is more complicated now than I wish it was but it has given birth to so much. I prefer it to BSD or MIT due to the share a like nature of GPL.

http://www.gnu.org/licenses/gpl-faq.en.html

⬐ csirac2

I'm no stranger to the GPL. I had a project which spent 9 months arguing with legal in a large institution to support 6 months work involving an independent open source contractor to work on a GPL'd thing.

But it is a restrictive license. Its "plague"-ness comes from its incompatibility with other licenses. Or at least, in the case of ZoL/CDDL and Linux/GPL, the crippling practical realities of the resulting kernel module binaries that are a derived work trying to impose restrictions on each other. That's why you can find precompiled modules on the ZoL website, but never in a distro.

That's a legitimate criticism, but as you say, also its defining feature.

⬐ dspillett

> If you make changes you must share the changes does not equal Plague Like.

You don't even have to share the changes with the unwashed masses, or even the original author, just the people you sell/give the resulting program/service too. Of course they are free to distribute the changes more freely, the license explicitly states it is a breach for you to try block that, but you don't have to.

⬐ baldfat

The GPL does not require you to release your modified version, or any part of it. You are free to make modifications and use them privately, without ever releasing them. This applies to organizations (including companies), too; an organization can make a modified version and use it internally without ever releasing it outside the organization.

But if you release the modified version to the public in some way, the GPL requires you to make the modified source code available to the program's users, under the GPL.

Thus, the GPL gives permission to release the modified program in certain ways, and not in other ways; but the decision of whether to release it is up to you.

⬐ dspillett

Exactly.

Though in the "a company or other organisation" situation IIRC your internal users count in the same way so far as the GPL is concerned so you should make the code available to them on request if you don't already and they are free to redistribute under the terms of the GPL. Another important caveat is the "upon request" part: you don't have to release the source to anyone unless explicitly requested so you don't have to release it automatically upon releasing a binary.

Of course if you just use the results for your own needs/entertainment there is no requirement to release anything at all.

⬐ switch007

- Use deduplication in a production environment [1]

[1] http://serverfault.com/questions/234475/zfs-destroying-dedup...

⬐ madez

You can use both together all day long even in your business. You must only not distribute both together.

⬐ SirMaster

Sure you can, Proxmox has distributed ZFS with it's custom Debian-based OS for over a year now.

ZFS comes pre-installed and the installer for Proxmox even gives you the options to install the OS directly onto a bootable zpool that is created automatically by the installer itself.

⬐ rsync

You can ZFS send and receive to rsync.net.[1]

[1] http://www.rsync.net/products/zfsintro.html

⬐ xaritas

This is a really great looking service. I couldn't find a contact form that wasn't for sales inquiries, but I thought you might like to know that your website is extremely buggy on my phone (iPhone 5s, iOS 9.0.2, Mobile Safari).

This is the bug: Scrolling causes the page to reload. Not even joking. Seems to happen on all pages.

Anyway, I took a look on my desktop and it works fine there. I might even sign up a few of my clients. Just not with my phone.

⬐ lectrick

> rsync.net now supports ZFS send and receive over SSH

> If you're not sure what this means, our product is Not For You.

Ha! Love it.