10 ms·

How ZFS continues to be better than Btrfs.

122 points by res0nat0r 14y ago

tbenst 14y ago
ZFS already has great support on Solaris and FreeBSD. If you're running linux check out http://zfsonlinux.org/ http://zfsonlinux.org/ - native kernel support that avoids the GPL incompatibility of Sun's zfs implementation (CDDL license).
- ksec 14y ago
  There is also SmartOS as well.
- ominous_prime 14y ago
  They don't avoid it; it's still CDDL, and it's still incompatible. This means that it can't be shipped within the kernel itself, so you have to build a module (which is marked as tainted) for your particular kernel. OpenAFS has this same issue BTW. http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue
- __alexs 14y ago
  I think it might be more sane to run GNU user space on Solaris (e.g. Nexenta, OpenIndiana) if you want ZFS that badly.
ibotty 14y ago
most points are valid (but known). ... but some are strange. why should a filesystem implement a cifs export? ok, zfs does it. but why should it?
- 4ad 14y ago
  It's not about who implements an SMB server (it's a separate layered filesystem, smbfs, on Solaris, not ZFS itself) but about the convenience of doing only: # zfs set sharesmb=on export/home and configuring access just by setting (with chmod) the Windows compatible ACLs on the ZFS filesystem itself. Authentication can also work as expected in a Windows shop. Doing all this in Samba is a PITA.
  - zdw 14y ago
    Has anyone tried to use Samba4's Active Directory implementation with Illumos ZFS SMB support (ie, without Samba's SMB implementation) ?
    - 4ad 14y ago
      No, why would they? It's not needed, a Solaris server can join a Windows Active Directory domain.
      - fragmede 14y ago
        I think zdw is asking if Samba can be the Active Directory controller while using the ZFS SMB stack.
        zdw 14y ago
        Exactly - if it worked, it would be a solid Windows server replacement for storage focused deployments.
  - ibotty 14y ago
    win compatible acls are incompatible to posix acls. that's hard to argue away.
    - 4ad 14y ago
      ZFS has NT ACLs, not POSIX ACLs.
- X-Istence 14y ago
  The file system doesn't implement it, the commands simply let you turn it on or off. CIFS is built into the kernel much like NFS on Solaris/OpenIndiana.
  - ibotty 14y ago
    but why should it care about it? it's a whole different stack...
_ak 14y ago
Claiming RAIDZ as an advantage is... weird. At least on a recent Solaris 10, it has absolutely terrible read/write performance.
- mdellabitta 14y ago
  It depends on your use case. In the world of preservation, ZFS is a godsend. If you're trying to run a database, copy-on-write is going to defeat you. Not that it isn't possible, but it's surely something you're going to have to work against. Fortunately, there are types of vdevs other than RAIDZ, and using SSDs for the ZIL can improve things as well. http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide#Tuning_ZFS_for_Database_Performance http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuni...
- barrkel 14y ago
  RAIDZ is about cheaper redundancy than mirroring; that's its optimization constraint, and by altering the ratio of drives to bit parity you can adjust to your risk taste. Since all drives need to be written and read for every read and write, the array will only be as fast as its slowest disk. But for large files, you still get the benefit of parallelism in drive bandwidth (rather than losing out from longer seeks). I see hefty throughput in video files on my home NAS, for example; over 400mb/sec locally, in practice it's limited by the gigabit Ethernet on my network.
majke 14y ago
Jeff Bonwick [1] the lead of ZFS development [2] seem to have disappeared after leaving Oracle in late 2010. I wonder what he is doing nowadays. [1] https://en.wikipedia.org/wiki/Jeff_Bonwick https://en.wikipedia.org/wiki/Jeff_Bonwick [2] https://en.wikipedia.org/wiki/Zfs https://en.wikipedia.org/wiki/Zfs
- bcantrill 14y ago
  Though Jeff is indisputably the father of ZFS, the ZFS team was (and is) much larger than Jeff. Many of the ZFS team (including its co-inventor, Matt Ahrens) are now at Delphix [1], and continue to be very active in the ZFS community[2] via illumos, its repository of record[3]. [1] http://www.youtube.com/watch?v=-zRN7XLCRhc#t=46m45s http://www.youtube.com/watch?v=-zRN7XLCRhc#t=46m45s [2] http://blog.delphix.com/matt/2011/11/01/zfs-10-year-anniversary/ http://blog.delphix.com/matt/2011/11/01/zfs-10-year-annivers... [3] http://blog.delphix.com/matt/2012/07/11/performance-of-zfs-destroy/ http://blog.delphix.com/matt/2012/07/11/performance-of-zfs-d...
  - blinkingled 14y ago
    Brian - if only a few enthusiast users can use Solaris derivatives on their hardware, do you not think ZFS is just relevant for the Enterprise folks? Are any ex-Sun,Oracle people putting in efforts for more X86 hardware compatibility? To me, ZFS and Dtrace are of no consequence if I can't use them on my own hardware. And I am sure there are many more people like me.
    - bcantrill 14y ago
      Virtually all of the work that we do in the illumos community is on x86 -- and not merely keeping it functional, but actively advancing the state of the art. For example, we at Joyent ported KVM to illumos last year[1], and since that time we have deployed many thousands of virtual (x86) machines into production on (x86) hardware running SmartOS, our illumos derivative.[2] [1] http://lwn.net/Articles/459754/ http://lwn.net/Articles/459754/ [2] http://smartos.org/ http://smartos.org/
armored_mammal 14y ago
Regardless of how good ZFS is, if it can't be shipped native on Linux nobody will care. Much. Though it is a neat file system. And I would love to see it in the Kernel. Unfortunately it's now controlled by Oracle so you're probably lucky that you can use it without hiring an 'storage consultant' for $100k+ a year.
- 4ad 14y ago
  Your first statement is unfortunately true, ZFS won't get much adoption in Linux if it's not in the kernel. However, your second statement is blatantly false. Much of ZFS development happens in the open in the illumos and FreeBSD communities. Joyent and Nexenta base their business on ZFS and pay people to work on the open source illumos. (Disclaimer, I used to work for Nexenta).
- timc3 14y ago
  I installed a openindiana ZFS system for my home just a few days ago. And I don't feel alone, now my collegues probably will also seriously consider it, because I can't stop singing it's praises. Best install I have done for some time.
- X-Istence 14y ago
  Those of us with data that we want to secure will care, and will run ZFS. Maybe not on Linux but on top of FreeBSD or OpenIndiana (in my case). Sorry, but Linux isn't the end all be all open source operating system, and is the last thing I will put into a production system where I care about my data and or stability.
koenigdavidmj 14y ago
A lot of these seem like btrfs user-interface problems. Is the actual filesystem incapable of doing all of these?
- SageRaven 14y ago
  To steal terminology from git, I'd say that brtfs has a lot of similar plumbing as ZFS, but hardly any of the porcelain. I think the lack of striped raid is the killer for a lot of people, in spite of the hate RAID5 seems to have gained lately. I went to a half-day Suse brunch event 2 months ago and got myself a eval copy of SLES v11sp2, just to check out brtfs. I tried to be mindful of the "it's not ZFS" attitude, and gave it a lot of leeway. Without going into the maturity of the code bse (I have no idea how stable it is), I found the capabilities and commands a bit cumbersome, counter-intuitive, and the FS as a whole just plain lacking. The article summed it up much more succinctly than I ever could. I've been using ZFS on my primary workstation on a daily basis since the early beta days of FreeBSD 8.0 (Jun '09, I believe), and it has been a pure joy to use. ZFS v28 (the last released version from Sun/OpenSolaris, I think) found on FreeBSD 9.x is rock-solid and has reasonable performance (as compared to the speed and memory problems seen in in earlier releases). I've put the filesystem through its paces, doing things that are rightfully called foolhardy, and I have never lost data. I've painted myself into a corner a few times (I curse the fact that you cannot remove hardware from the pool, as with Linux or AIX LVM), but never have I lost data when redundancy was in use. I have had bad sectors crop up on a single-disk zfs pool (single-copy of data, should have known better), and a "scrub" let me know exactly which files had incorrectable problems. Heck, I routinely flip the switch on my PSU when I'm too lazy to walk around my desk to do a proper shutdown, and it comes right back at next boot, no lengthy fsck, no data loss. I usually scrub monthly to check for errors, and otherwise I don't do much maintenance. Right now, I have 6 2TB Seagate "green" drives in a raidz2 array (raid5-like with 2 parity disks). One disk has been removed due to errors, so I still have a spare disk to tide me over until I can afford a replacement. It runs very well. I wish native ZFS crypto was available. Right now, each physical device is fully-encrypted with FreeBSD's "geli" (customer data, tax records, etc.), so ZFS doesn't even really have full domain over the physical devices, which makes it even more impressive that I've never lost data. I will say that enabling compression and/or dedup will cause performance issues. I've got an 8-core AMD processor (XF-1850 -- hardware AES support, yay!) w/ 16GB of DDR3, and I get interactive desktop lag when heavy I/O is going against compressed and/or de-duped data. I don't know if this is a FreeBSD scheduling issue , or inherent with ZFS (any Solaris users want to comment?). Since it was mostly just to test (not like I need the space savings), I just do without. In any case, I hope Linux's ZFS native kernel port stabilizes. brtfs just isn't there yet.
zobzu 14y ago
meh the fan-articles are so hard to read. "fact!" "unlikely!" "using these facts!" "maybe its bad but at least zfs has it!" well dude, here's a fact: http://lwn.net/Articles/506244/ http://lwn.net/Articles/506244/ have you even used btrfs lately? because that collides with some of your "facts" so sure, zfs has advantages over btrfs and is arguably better right now, but the latter is still experimental. the main reason for btrfs is the proper licensing for the Linux kernel, anyway - else we'd all be hacking on zfs since day one and there wouldn't even have been a need for btrfs.
- dkhenry 14y ago
  Also btrfs has been recieving substantial upgrades every kernel revision. Already its worlds better then it was in the 2.6.x series of kernel and they are finally getting around to tuning everything for performance. The truth is some of those "factS" are true, but most of them are pointless.
tjoff 14y ago
What a non-article. ZFS is more mature than an unmature and unstable filesystem? Really? The article is also full of irrelevant details and downright faulty statements. ZFS is more stable. Yeah, if it wasn't that'd be really bad. Keep in mind that when ZFS was new it wasn't particularly stable either, despite the arguments put forward - a file system must mature with time. ZFS isn't for the typical enthusiast/home-user. It can't be more apparent than the fact that ZFS dosesn't have a fsck-tool, why doesn't ZFS need a fsck-tool? Because every time you'd need it you just restore your backups from tape instead ( Should ZFS have a fsck tool? http://www.osnews.com/story/22423/Should_ZFS_Have_a_fsck_Tool_/ http://www.osnews.com/story/22423/Should_ZFS_Have_a_fsck_Too... ) You can yank the power cord of your machine -- you will never lose a single byte of anything committed to the disk. ZFS is always consistent on disk, and never trusts any faulty data (that might have become damaged because of hardware issues). Nope. Never mind that ZFS assumes that harddrives works to spec, which consumer drives do not (keep in mind that ZFS is designed to be able to run on consumer drives). Meaning that you can not yank the power cord to your machine (if you care about your data). ZFS truly is awesome, it makes all other easily available linux filesystems look really, really, really poor. Which truly sucks, if you use linux (honestly, I haven't checked the linux alternatives for ZFS but I have a really hard time believing that anyone should trust such an untested solution, just use a stable linux filesystem and wait, patiently, for btrfs). So, along comes btrfs that mimics the feature-set of ZFS but brings along many advantages (much thanks to it being developed much later). And btrfs has a different target group. Btrfs is much better adapted for home use (it even has a fsck-tool!). But, btrfs isn't stable (and it shouldn't be trusted in the near future)... And I just can't fathom how you can write such an comparison between btrfs and ZFS today, it just doesn't make sense. When btrfs is stable and mature things should get interesting.
- lmm 14y ago
  As an enthusiast/home-user I use ZFS, and it has saved my data in situations where no linux filesystem I've tried would. XFS doesn't have an fsck either; more to the point, more does btrfs, so you can't really give that as a reason why btrfs is more suitable for home users.
  - 14y ago
tytso 14y ago
ZFS has a lot of cool features. Granted. But the question is whether or not you need those features, and are they worth the cost that they incur. Especially in the days of VM's, memory is often at a huge premium --- consider how much you have to pay for extra memory. This is not surprising, because if you try to pack a couple of dozen VM's on a single server, memory very often ends up being the critically short resource (servers have only so many DIMM slots, and high density memory modules are expensive). ZFS might be great if you're running a file server where you can pack many gigabytes of memory into a server and not use it for anything else. But if you are trying to run a cloud or VM server, where you are trying to pack lots of jobs on a single machine, the cost/benefit ratio of a copy-on-write file system (whether it is btrfs or ZFS) may not be worth it.
- petsos 14y ago
  Sure, give up deduplication, snapshots, raidz, self healing and more for a fuzzy cost/benefit ratio that is based on no data.
- X-Istence 14y ago
  Take a look at SmartOS which is based on Illumos. Has KVM and is used extensively by Joyent themselves. Sorry, but having your underlying storage be rock solid is absolutely crucial for VM's.
antonios 14y ago
Of course it's better. It's a filesystem that has had years to mature, while Btrfs is _still_ in development. There isn't even a comparison.
StavrosK 14y ago
I definitely agree that ZFS is fantastic, the best thing since sliced bread and better than anything else ever to exist. However, I can only run btrfs on Ubuntu natively. Therefore, to me, btrfs is better than ZFS.
- Locke1689 14y ago
  You can easily compile ZFS support into your kernel.
- rewtraw 14y ago
  For what it's worth, I've had very good luck with zfs-on-linux on my 12.04 system. Multiple pools, largest is 20TB. Zero problems after a year of use. Switched from mdadm/xfs due to major data loss from corruption, and I don't plan on looking back. http://zfsonlinux.org/ http://zfsonlinux.org/
  - StavrosK 14y ago
    That's very helpful, thank you. I'll give it a shot, although I remember this being a few versions behind the BSD version? I have a NAS that uses mdadm now (it did save me when one disk went completely bust), but RAIDZ sounds even better.
    - rewtraw 14y ago
      Wikipedia has a decent comparison here: http://en.wikipedia.org/wiki/ZFS#Comparisons http://en.wikipedia.org/wiki/ZFS#Comparisons looks like both the BSD and native Linux port are on version 28.
- ajross 14y ago
  Exactly. ZFS was deliberately released with a license designed to keep it out of the kernel. It's unavailable to the Linux community, so people use what they have and work on replacements. The controversy isn't technical, it's legal. And it's not resolvable by feature lists and fanboi flaming. ZFS is great, I'm sure. But btrfs is great too and rapidly improving. I don't think the Linux world has much to worry about.
mey 14y ago
As an outsider to the vitriol between ZFS and the Linux Filesystem community, why is there so much aggression here? People don't seem to be screaming up and down about NTFS. If you are operating at a scale where this management of data matters, aren't you doing you own analysis and proving?
- acdha 14y ago
  When ZFS was released, Sun made some strong statements about Linux filesystems, particularly regarding data integrity and ease of management. As a Linux sysadmin with a fairly large amount of data, I thought those were completely warranted but unfortunately some people took it as attacks rather than considering the technical merits. Toss in yet another licensing flamewar and the more vocal parts Linux community wasted a few years pretending the gap would go away if they ignored it. This is the same reason why Linux doesn't have a viable DTrace competitor: the “what's wrong with kdb?” attitude started with Linus and it took way too long for the near-unanimous sysadmin voice to be heard.
chaostheory 14y ago
Does any of this matter with ZFS's license issues?
- dap 14y ago
  Isn't it absurd that someone would consider ignoring all of those points about technical details and user experience of free software because of license issues with other "free" software? As a member of the illumos community, I long ago turned the question around: given ZFS, DTrace, Zones, and the rest, all available in a free (as in speech) operating system, why would I use a different system that prohibits incorporating all this valuable free software?
  - chaostheory 14y ago
    > Isn't it absurd that someone would consider ignoring all of those points about technical details and user experience of free software because of license issues with other "free" software? It depends on perspective. I think it's ridiculous that someone would even put out a whole distro that's free and useful, and I am really grateful for that. > why would I use a different system that prohibits incorporating all this valuable free software? In my case it's simple: I don't have the time or energy to put out a distro that conforms to everything that I want.
neverm0re 14y ago
HAMMER2 ( http://apollo.backplane.com/DFlyMisc/hammer2.txt http://apollo.backplane.com/DFlyMisc/hammer2.txt ) is far more interesting to me than sitting around waiting for someone to care enough about Btrfs to finish polishing it until it's ready. The world is ready for a post-ZFS file system, it's just a matter of who delivers first and with an acceptable license. Btrfs hasn't at all capitalized on the significant interest surrounding it, which is a shame.
happywolf 14y ago
I suspect alot of people who nickpick ZFS do not have much practical experience using ZFS. My home entertainment center has been running ZFS since the OpenSolaris era, then switched to FreeBSD and so far, no _single_ loss of data. Btrfs maybe a fine fs, but I don't see any pressing need at my end to switch even if Btrfs is ready. Linux is absolutely a wonderful OS, but FreeBSD meets my requirements. Frankly, my server runs a minimal set of services and I don't run applications from there. Even though Linux has much more packages than FreeBSD, I don't need those. Thank you very much.
caf 14y ago
btrfs cannot show you how much disk space is being referred to by each subvolume, as its used and free space tracking is only per pool. The only way to see how much space a particular subvolume is taking is to use du, which gets slower the bigger the subvolume gets. This is no longer true. As of Linux 3.6, btrfs has the ability to apply quotas to subvolumes.

122 points by res0nat0r 14y ago

ZFS already has great support on Solaris and FreeBSD. If you're running linux check out http://zfsonlinux.org/ http://zfsonlinux.org/ - native kernel support that avoids the GPL incompatibility of Sun's zfs implementation (CDDL license).

ksec 14y ago
There is also SmartOS as well.
ominous_prime 14y ago
They don't avoid it; it's still CDDL, and it's still incompatible. This means that it can't be shipped within the kernel itself, so you have to build a module (which is marked as tainted) for your particular kernel. OpenAFS has this same issue BTW. http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue http://zfsonlinux.org/faq.html#WhatAboutTheLicensingIssue
__alexs 14y ago
I think it might be more sane to run GNU user space on Solaris (e.g. Nexenta, OpenIndiana) if you want ZFS that badly.

ibotty 14y ago

most points are valid (but known). ... but some are strange. why should a filesystem implement a cifs export? ok, zfs does it. but why should it?

4ad 14y ago
It's not about who implements an SMB server (it's a separate layered filesystem, smbfs, on Solaris, not ZFS itself) but about the convenience of doing only: # zfs set sharesmb=on export/home and configuring access just by setting (with chmod) the Windows compatible ACLs on the ZFS filesystem itself. Authentication can also work as expected in a Windows shop. Doing all this in Samba is a PITA.
- zdw 14y ago
  Has anyone tried to use Samba4's Active Directory implementation with Illumos ZFS SMB support (ie, without Samba's SMB implementation) ?
  - 4ad 14y ago
    No, why would they? It's not needed, a Solaris server can join a Windows Active Directory domain.
    - fragmede 14y ago
      I think zdw is asking if Samba can be the Active Directory controller while using the ZFS SMB stack.
      - zdw 14y ago
        Exactly - if it worked, it would be a solid Windows server replacement for storage focused deployments.
- ibotty 14y ago
  win compatible acls are incompatible to posix acls. that's hard to argue away.
  - 4ad 14y ago
    ZFS has NT ACLs, not POSIX ACLs.
X-Istence 14y ago
The file system doesn't implement it, the commands simply let you turn it on or off. CIFS is built into the kernel much like NFS on Solaris/OpenIndiana.
- ibotty 14y ago
  but why should it care about it? it's a whole different stack...

_ak 14y ago

Claiming RAIDZ as an advantage is... weird. At least on a recent Solaris 10, it has absolutely terrible read/write performance.

mdellabitta 14y ago
It depends on your use case. In the world of preservation, ZFS is a godsend. If you're trying to run a database, copy-on-write is going to defeat you. Not that it isn't possible, but it's surely something you're going to have to work against. Fortunately, there are types of vdevs other than RAIDZ, and using SSDs for the ZIL can improve things as well. http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide#Tuning_ZFS_for_Database_Performance http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuni...
barrkel 14y ago
RAIDZ is about cheaper redundancy than mirroring; that's its optimization constraint, and by altering the ratio of drives to bit parity you can adjust to your risk taste. Since all drives need to be written and read for every read and write, the array will only be as fast as its slowest disk. But for large files, you still get the benefit of parallelism in drive bandwidth (rather than losing out from longer seeks). I see hefty throughput in video files on my home NAS, for example; over 400mb/sec locally, in practice it's limited by the gigabit Ethernet on my network.

majke 14y ago

Jeff Bonwick [1] the lead of ZFS development [2] seem to have disappeared after leaving Oracle in late 2010. I wonder what he is doing nowadays. [1] https://en.wikipedia.org/wiki/Jeff_Bonwick https://en.wikipedia.org/wiki/Jeff_Bonwick [2] https://en.wikipedia.org/wiki/Zfs https://en.wikipedia.org/wiki/Zfs

bcantrill 14y ago
Though Jeff is indisputably the father of ZFS, the ZFS team was (and is) much larger than Jeff. Many of the ZFS team (including its co-inventor, Matt Ahrens) are now at Delphix [1], and continue to be very active in the ZFS community[2] via illumos, its repository of record[3]. [1] http://www.youtube.com/watch?v=-zRN7XLCRhc#t=46m45s http://www.youtube.com/watch?v=-zRN7XLCRhc#t=46m45s [2] http://blog.delphix.com/matt/2011/11/01/zfs-10-year-anniversary/ http://blog.delphix.com/matt/2011/11/01/zfs-10-year-annivers... [3] http://blog.delphix.com/matt/2012/07/11/performance-of-zfs-destroy/ http://blog.delphix.com/matt/2012/07/11/performance-of-zfs-d...
- blinkingled 14y ago
  Brian - if only a few enthusiast users can use Solaris derivatives on their hardware, do you not think ZFS is just relevant for the Enterprise folks? Are any ex-Sun,Oracle people putting in efforts for more X86 hardware compatibility? To me, ZFS and Dtrace are of no consequence if I can't use them on my own hardware. And I am sure there are many more people like me.
  - bcantrill 14y ago
    Virtually all of the work that we do in the illumos community is on x86 -- and not merely keeping it functional, but actively advancing the state of the art. For example, we at Joyent ported KVM to illumos last year[1], and since that time we have deployed many thousands of virtual (x86) machines into production on (x86) hardware running SmartOS, our illumos derivative.[2] [1] http://lwn.net/Articles/459754/ http://lwn.net/Articles/459754/ [2] http://smartos.org/ http://smartos.org/

armored_mammal 14y ago

Regardless of how good ZFS is, if it can't be shipped native on Linux nobody will care. Much. Though it is a neat file system. And I would love to see it in the Kernel. Unfortunately it's now controlled by Oracle so you're probably lucky that you can use it without hiring an 'storage consultant' for $100k+ a year.

4ad 14y ago
Your first statement is unfortunately true, ZFS won't get much adoption in Linux if it's not in the kernel. However, your second statement is blatantly false. Much of ZFS development happens in the open in the illumos and FreeBSD communities. Joyent and Nexenta base their business on ZFS and pay people to work on the open source illumos. (Disclaimer, I used to work for Nexenta).
timc3 14y ago
I installed a openindiana ZFS system for my home just a few days ago. And I don't feel alone, now my collegues probably will also seriously consider it, because I can't stop singing it's praises. Best install I have done for some time.
X-Istence 14y ago
Those of us with data that we want to secure will care, and will run ZFS. Maybe not on Linux but on top of FreeBSD or OpenIndiana (in my case). Sorry, but Linux isn't the end all be all open source operating system, and is the last thing I will put into a production system where I care about my data and or stability.

koenigdavidmj 14y ago

A lot of these seem like btrfs user-interface problems. Is the actual filesystem incapable of doing all of these?

SageRaven 14y ago
To steal terminology from git, I'd say that brtfs has a lot of similar plumbing as ZFS, but hardly any of the porcelain. I think the lack of striped raid is the killer for a lot of people, in spite of the hate RAID5 seems to have gained lately. I went to a half-day Suse brunch event 2 months ago and got myself a eval copy of SLES v11sp2, just to check out brtfs. I tried to be mindful of the "it's not ZFS" attitude, and gave it a lot of leeway. Without going into the maturity of the code bse (I have no idea how stable it is), I found the capabilities and commands a bit cumbersome, counter-intuitive, and the FS as a whole just plain lacking. The article summed it up much more succinctly than I ever could. I've been using ZFS on my primary workstation on a daily basis since the early beta days of FreeBSD 8.0 (Jun '09, I believe), and it has been a pure joy to use. ZFS v28 (the last released version from Sun/OpenSolaris, I think) found on FreeBSD 9.x is rock-solid and has reasonable performance (as compared to the speed and memory problems seen in in earlier releases). I've put the filesystem through its paces, doing things that are rightfully called foolhardy, and I have never lost data. I've painted myself into a corner a few times (I curse the fact that you cannot remove hardware from the pool, as with Linux or AIX LVM), but never have I lost data when redundancy was in use. I have had bad sectors crop up on a single-disk zfs pool (single-copy of data, should have known better), and a "scrub" let me know exactly which files had incorrectable problems. Heck, I routinely flip the switch on my PSU when I'm too lazy to walk around my desk to do a proper shutdown, and it comes right back at next boot, no lengthy fsck, no data loss. I usually scrub monthly to check for errors, and otherwise I don't do much maintenance. Right now, I have 6 2TB Seagate "green" drives in a raidz2 array (raid5-like with 2 parity disks). One disk has been removed due to errors, so I still have a spare disk to tide me over until I can afford a replacement. It runs very well. I wish native ZFS crypto was available. Right now, each physical device is fully-encrypted with FreeBSD's "geli" (customer data, tax records, etc.), so ZFS doesn't even really have full domain over the physical devices, which makes it even more impressive that I've never lost data. I will say that enabling compression and/or dedup will cause performance issues. I've got an 8-core AMD processor (XF-1850 -- hardware AES support, yay!) w/ 16GB of DDR3, and I get interactive desktop lag when heavy I/O is going against compressed and/or de-duped data. I don't know if this is a FreeBSD scheduling issue , or inherent with ZFS (any Solaris users want to comment?). Since it was mostly just to test (not like I need the space savings), I just do without. In any case, I hope Linux's ZFS native kernel port stabilizes. brtfs just isn't there yet.

zobzu 14y ago

meh the fan-articles are so hard to read. "fact!" "unlikely!" "using these facts!" "maybe its bad but at least zfs has it!" well dude, here's a fact: http://lwn.net/Articles/506244/ http://lwn.net/Articles/506244/ have you even used btrfs lately? because that collides with some of your "facts" so sure, zfs has advantages over btrfs and is arguably better right now, but the latter is still experimental. the main reason for btrfs is the proper licensing for the Linux kernel, anyway - else we'd all be hacking on zfs since day one and there wouldn't even have been a need for btrfs.

dkhenry 14y ago
Also btrfs has been recieving substantial upgrades every kernel revision. Already its worlds better then it was in the 2.6.x series of kernel and they are finally getting around to tuning everything for performance. The truth is some of those "factS" are true, but most of them are pointless.

tjoff 14y ago

What a non-article. ZFS is more mature than an unmature and unstable filesystem? Really? The article is also full of irrelevant details and downright faulty statements. ZFS is more stable. Yeah, if it wasn't that'd be really bad. Keep in mind that when ZFS was new it wasn't particularly stable either, despite the arguments put forward - a file system must mature with time. ZFS isn't for the typical enthusiast/home-user. It can't be more apparent than the fact that ZFS dosesn't have a fsck-tool, why doesn't ZFS need a fsck-tool? Because every time you'd need it you just restore your backups from tape instead ( Should ZFS have a fsck tool? http://www.osnews.com/story/22423/Should_ZFS_Have_a_fsck_Tool_/ http://www.osnews.com/story/22423/Should_ZFS_Have_a_fsck_Too... ) You can yank the power cord of your machine -- you will never lose a single byte of anything committed to the disk. ZFS is always consistent on disk, and never trusts any faulty data (that might have become damaged because of hardware issues). Nope. Never mind that ZFS assumes that harddrives works to spec, which consumer drives do not (keep in mind that ZFS is designed to be able to run on consumer drives). Meaning that you can not yank the power cord to your machine (if you care about your data). ZFS truly is awesome, it makes all other easily available linux filesystems look really, really, really poor. Which truly sucks, if you use linux (honestly, I haven't checked the linux alternatives for ZFS but I have a really hard time believing that anyone should trust such an untested solution, just use a stable linux filesystem and wait, patiently, for btrfs). So, along comes btrfs that mimics the feature-set of ZFS but brings along many advantages (much thanks to it being developed much later). And btrfs has a different target group. Btrfs is much better adapted for home use (it even has a fsck-tool!). But, btrfs isn't stable (and it shouldn't be trusted in the near future)... And I just can't fathom how you can write such an comparison between btrfs and ZFS today, it just doesn't make sense. When btrfs is stable and mature things should get interesting.

lmm 14y ago
As an enthusiast/home-user I use ZFS, and it has saved my data in situations where no linux filesystem I've tried would. XFS doesn't have an fsck either; more to the point, more does btrfs, so you can't really give that as a reason why btrfs is more suitable for home users.
- 14y ago

tytso 14y ago

ZFS has a lot of cool features. Granted. But the question is whether or not you need those features, and are they worth the cost that they incur. Especially in the days of VM's, memory is often at a huge premium --- consider how much you have to pay for extra memory. This is not surprising, because if you try to pack a couple of dozen VM's on a single server, memory very often ends up being the critically short resource (servers have only so many DIMM slots, and high density memory modules are expensive). ZFS might be great if you're running a file server where you can pack many gigabytes of memory into a server and not use it for anything else. But if you are trying to run a cloud or VM server, where you are trying to pack lots of jobs on a single machine, the cost/benefit ratio of a copy-on-write file system (whether it is btrfs or ZFS) may not be worth it.

petsos 14y ago
Sure, give up deduplication, snapshots, raidz, self healing and more for a fuzzy cost/benefit ratio that is based on no data.
X-Istence 14y ago
Take a look at SmartOS which is based on Illumos. Has KVM and is used extensively by Joyent themselves. Sorry, but having your underlying storage be rock solid is absolutely crucial for VM's.

antonios 14y ago

Of course it's better. It's a filesystem that has had years to mature, while Btrfs is _still_ in development. There isn't even a comparison.

StavrosK 14y ago

I definitely agree that ZFS is fantastic, the best thing since sliced bread and better than anything else ever to exist. However, I can only run btrfs on Ubuntu natively. Therefore, to me, btrfs is better than ZFS.

Locke1689 14y ago
You can easily compile ZFS support into your kernel.
rewtraw 14y ago
For what it's worth, I've had very good luck with zfs-on-linux on my 12.04 system. Multiple pools, largest is 20TB. Zero problems after a year of use. Switched from mdadm/xfs due to major data loss from corruption, and I don't plan on looking back. http://zfsonlinux.org/ http://zfsonlinux.org/
- StavrosK 14y ago
  That's very helpful, thank you. I'll give it a shot, although I remember this being a few versions behind the BSD version? I have a NAS that uses mdadm now (it did save me when one disk went completely bust), but RAIDZ sounds even better.
  - rewtraw 14y ago
    Wikipedia has a decent comparison here: http://en.wikipedia.org/wiki/ZFS#Comparisons http://en.wikipedia.org/wiki/ZFS#Comparisons looks like both the BSD and native Linux port are on version 28.
ajross 14y ago
Exactly. ZFS was deliberately released with a license designed to keep it out of the kernel. It's unavailable to the Linux community, so people use what they have and work on replacements. The controversy isn't technical, it's legal. And it's not resolvable by feature lists and fanboi flaming. ZFS is great, I'm sure. But btrfs is great too and rapidly improving. I don't think the Linux world has much to worry about.

mey 14y ago

As an outsider to the vitriol between ZFS and the Linux Filesystem community, why is there so much aggression here? People don't seem to be screaming up and down about NTFS. If you are operating at a scale where this management of data matters, aren't you doing you own analysis and proving?

acdha 14y ago
When ZFS was released, Sun made some strong statements about Linux filesystems, particularly regarding data integrity and ease of management. As a Linux sysadmin with a fairly large amount of data, I thought those were completely warranted but unfortunately some people took it as attacks rather than considering the technical merits. Toss in yet another licensing flamewar and the more vocal parts Linux community wasted a few years pretending the gap would go away if they ignored it. This is the same reason why Linux doesn't have a viable DTrace competitor: the “what's wrong with kdb?” attitude started with Linus and it took way too long for the near-unanimous sysadmin voice to be heard.

chaostheory 14y ago

Does any of this matter with ZFS's license issues?

dap 14y ago
Isn't it absurd that someone would consider ignoring all of those points about technical details and user experience of free software because of license issues with other "free" software? As a member of the illumos community, I long ago turned the question around: given ZFS, DTrace, Zones, and the rest, all available in a free (as in speech) operating system, why would I use a different system that prohibits incorporating all this valuable free software?
- chaostheory 14y ago
  > Isn't it absurd that someone would consider ignoring all of those points about technical details and user experience of free software because of license issues with other "free" software? It depends on perspective. I think it's ridiculous that someone would even put out a whole distro that's free and useful, and I am really grateful for that. > why would I use a different system that prohibits incorporating all this valuable free software? In my case it's simple: I don't have the time or energy to put out a distro that conforms to everything that I want.

neverm0re 14y ago

HAMMER2 ( http://apollo.backplane.com/DFlyMisc/hammer2.txt http://apollo.backplane.com/DFlyMisc/hammer2.txt ) is far more interesting to me than sitting around waiting for someone to care enough about Btrfs to finish polishing it until it's ready. The world is ready for a post-ZFS file system, it's just a matter of who delivers first and with an acceptable license. Btrfs hasn't at all capitalized on the significant interest surrounding it, which is a shame.

happywolf 14y ago

I suspect alot of people who nickpick ZFS do not have much practical experience using ZFS. My home entertainment center has been running ZFS since the OpenSolaris era, then switched to FreeBSD and so far, no _single_ loss of data. Btrfs maybe a fine fs, but I don't see any pressing need at my end to switch even if Btrfs is ready. Linux is absolutely a wonderful OS, but FreeBSD meets my requirements. Frankly, my server runs a minimal set of services and I don't run applications from there. Even though Linux has much more packages than FreeBSD, I don't need those. Thank you very much.

caf 14y ago

btrfs cannot show you how much disk space is being referred to by each subvolume, as its used and free space tracking is only per pool. The only way to see how much space a particular subvolume is taking is to use du, which gets slower the bigger the subvolume gets. This is no longer true. As of Linux 3.6, btrfs has the ability to apply quotas to subvolumes.