Linus: Don't Use ZFS • Hacker News Board

Re: Linus: Don't Use ZFS

#31

Post by Jonnax » Thu, Jan 09, 2020, 9:01 PM UTC

rleigh wrote: post #24

Covzire wrote: post #13

Earlier quoted context omitted.

Relevant bits: "Don't use ZFS. It's that simple. It was always more of a buzzword than anything else, I feel, and the licensing issues just make it a non-starter for me. The benchmarks I've seen do not make ZFS look all that great. And as far as I can tell, it has no real maintenance behind it either any more, so from a long-term stability standpoint, why would you ever want to use it in the first place?"

Not sure where that belief comes from. But it might be that many benchmarks are naive and compare it against other filesystems in single-disc setups with zero tuning. Since its metadata overheads are higher, it's definitely slower in this scenario. However, put a pool onto an array of discs and tune it a little, and the performance scales up and up leaving all Linux-native filesystems, and LVM/dm/mdraid, well behind.…

Have you seen any benchmarks for the scenario you've described?

Re: Linus: Don't Use ZFS

#32

Post by the8472 » Thu, Jan 09, 2020, 9:01 PM UTC

reacharavindh wrote: post #10

As a heavy user of ZFS and Linux, what else is there that even comes close to what ZFS offers? I want cheap and reliable snapshots, export & import of file systems like ZFS datasets, simple compression, caching facilities(like SLOG and ARC) and decent performance.

btrfs + dm-cache? throw in dm-raid if you want raid5.

Re: Linus: Don't Use ZFS

#33

Post by jessant » Thu, Jan 09, 2020, 9:01 PM UTC

fgonzag wrote: post #25

reacharavindh wrote: post #10

As a heavy user of ZFS and Linux, what else is there that even comes close to what ZFS offers? I want cheap and reliable snapshots, export & import of file systems like ZFS datasets, simple compression, caching facilities(like SLOG and ARC) and decent performance.

Bcachefs is probably the only thing that will get there. The codebase is clean and we'll mantained, built from solid technology (bcache) and will include most of the ZFS niceties. I just wish more companies would sponsor de project and stop wasting money on BTRFS

Snapshots don't seem to be done yet.

Re: Linus: Don't Use ZFS

#34

Post by usefulcat » Thu, Jan 09, 2020, 9:01 PM UTC

Covzire wrote: post #13

Hamuko wrote: post #7

Earlier quoted context omitted.

That's his reasoning for not merging ZFS code, not for generally avoiding ZFS.

Relevant bits: "Don't use ZFS. It's that simple. It was always more of a buzzword than anything else, I feel, and the licensing issues just make it a non-starter for me. The benchmarks I've seen do not make ZFS look all that great. And as far as I can tell, it has no real maintenance behind it either any more, so from a long-term stability standpoint, why would you ever want to use it in the first place?"

I think speed is not the primary reason many (most?) people use ZFS; I think it's mostly about stability, reliability and maintainability.

Re: Linus: Don't Use ZFS

#35

Post by btilly » Thu, Jan 09, 2020, 9:02 PM UTC

Hamuko wrote: post #7

Jonnax wrote: post #4

Here's his reasoning: "honestly, there is no way I can merge any of the ZFS efforts until I get an official letter from Oracle that is signed by their main legal counsel or preferably by Larry Ellison himself that says that yes, it's ok to do so and treat the end result as GPL'd. Other people think it can be ok to merge ZFS code into the kernel and that the module interface makes it ok, and that's their decision. But…

That's his reasoning for not merging ZFS code, not for generally avoiding ZFS.

Here are his reasons for generally avoiding ZFS from what I consider most important to least.

- The kernel team may break it at any time, and won't care if they do.

- It doesn't seem to be well-maintained.

- Performance is not that great compared to the alternatives.

- Using it opens you up to the threat of lawsuits from Oracle. Given history, this is a real threat. (This is one that should be high for Linus but not for me - there is no conceivable reason that Oracle would want to threaten me with a lawsuit.)

Re: Linus: Don't Use ZFS

#36

Post by ghaff » Thu, Jan 09, 2020, 9:02 PM UTC

Hamuko wrote: post #7

Jonnax wrote: post #4

Here's his reasoning: "honestly, there is no way I can merge any of the ZFS efforts until I get an official letter from Oracle that is signed by their main legal counsel or preferably by Larry Ellison himself that says that yes, it's ok to do so and treat the end result as GPL'd. Other people think it can be ok to merge ZFS code into the kernel and that the module interface makes it ok, and that's their decision. But…

That's his reasoning for not merging ZFS code, not for generally avoiding ZFS.

And he was doing fine up to that point. For IMO good reasons, ZFS will likely never be merged into Linux. And filesystem kernel modules from third parties have a pretty long history of breakage issues going back to some older Unixes.

That's going to be plenty of reason not to use ZFS for most people. The licensing by itself is also certainly a showstopper for many.

But I'm not sure his other comments are really fair and, had Oracle relicensed ZFS n years back, ZFS would almost certainly be shipping with Linux, whether or not as the typical default I can't say. It certainly wasn't just a buzzword and there were a number of interesting aspects to its approach.

Re: Linus: Don't Use ZFS

#37

Post by fgonzag » Thu, Jan 09, 2020, 9:03 PM UTC

jessant wrote: post #33

fgonzag wrote: post #25

Earlier quoted context omitted.

Bcachefs is probably the only thing that will get there. The codebase is clean and we'll mantained, built from solid technology (bcache) and will include most of the ZFS niceties. I just wish more companies would sponsor de project and stop wasting money on BTRFS

Snapshots don't seem to be done yet.

That's exactly why I said it's probably the only one that will get there.

Re: Linus: Don't Use ZFS

#38

Post by jessant » Thu, Jan 09, 2020, 9:03 PM UTC

nosequel wrote: post #30

jessant wrote: post #26

Earlier quoted context omitted.

Does btrfs met your requirements?

btrfs is not at all reliable, so if you care about your files staying working files, it probably doesn't meet your requirements. It is like the MongoDB 0.1 of filesystems.

Seems pretty reliable these days. Are you commenting based upon personal experience? If so, when was it that you used btrfs?

Re: Linus: Don't Use ZFS

#39

Post by bayindirh » Thu, Jan 09, 2020, 9:03 PM UTC

rkagerer wrote: post #21

gigatexal wrote: post #5

He mentioned that he didn’t think it was being maintained. It’s more or less been formed no? Has Linus not seen the work that the OpenZFS folks are doing? ZFS is amazing and I would soon go to a BSD flavor with a fun set of user land utilities than give it up.

He also feels ZFS "was always more of a buzzword than anything else". Yikes.

Honestly, I wouldn't bash him for this comment. Not everyone runs a 10+ TB array at their home for storage and backup purposes.

ZFS doesn't primarily target single disks and small arrays anyway. :)

Re: Linus: Don't Use ZFS

#40

Post by djsumdog » Thu, Jan 09, 2020, 9:04 PM UTC

So, is Linus pretty much the same guy? I know he took some time off and the kernel team adopted a code-o-conduct, and had that introspective e-mail ... but now that he's back ... is it any different?