ZFS 2.3 released with ZFS raidz expansion • Hacker News Board

Re: ZFS 2.3 released with ZFS raidz expansion

#251

Post by ryao » Tue, Jan 14, 2025, 9:20 PM UTC

pdimitar wrote: post #240

ryao wrote: post #239

Earlier quoted context omitted.

You can do this on ZFS today with `zpool create -o ashift=14 ...`.

Yeah I know, thanks. But ZFS still mostly requires drives with the same sizes. My main NAS is like that but I can't expand it even though I want to, with drives of different sizes I have lying around, and I am not keen on spending for new HDDs right now. So I thought I'll make a secondary NAS with bcachefs and all the spare drives I have. As for ZFS, I'll be buying some extra drives later this year and will make use…

If you don’t care about redundancy, you could add all of them as top level vdevs and then ZFS will happily use all of the space on them until one fails. Performance should be great until there is a failure. Just have good backups.

Re: ZFS 2.3 released with ZFS raidz expansion

#252

Post by doctorpangloss » Tue, Jan 14, 2025, 9:31 PM UTC

poisonborz wrote: post #59

I just don't get it how the Windows world - by far the largest PC platform per userbase - still doesn't have any answer to ZFS. Microsoft had WinFS and then ReFS but it's on the backburner and while there is active development (Win11 ships some bits time to time) release is nowhere in sight. There are some lone warriors trying the giant task of creating a ZFS compatibility layer with some projects, but they are far f…

The same reason file deduplication is not enabled for client Windows: greed.

For example, there are numerous new file systems people use: OneDrive, Google Drive, iCloud Storage. Do you get it?

Re: ZFS 2.3 released with ZFS raidz expansion

#253

Post by ryao » Tue, Jan 14, 2025, 9:47 PM UTC

jeltz wrote: post #244

ryao wrote: post #234

Earlier quoted context omitted.

ZFS will outscale ext4 in parallel workloads with ease. XFS will often scale better than ext4, but if you use L2ARC and SLOG devices, it is no contest. On top of that, you can use compression for an additional boost. You might also find ZFS outperforms both of them in read workloads on single disks where ARC minimizes cold cache effects. When I began using ZFS for my rootfs, I noticed my desktop environment became mo…

Not on most database workloads. There zfs does not scale very well.

Percona and many others who benchmarked this properly would disagree with you. Percona found that ext4 and ZFS performed similarly when given identical hardware (with proper tuning of ZFS):

https://www.percona.com/blog/mysql-zfs-performance-update/

In this older comparison where they did not initially tune ZFS properly for the database, they found XFS to perform better, only for ZFS to outperform it when tuning was done and a L2ARC was added:

https://www.percona.com/blog/about-zfs-performance/

This is roughly what others find when they take the time to do proper tuning and benchmarks. ZFS outscales both ext4 and XFS, since it is a multiple block device filesystem that supports tiered storage while ext4 and XFS are single block device filesystems (with the exception of supporting journals on external drives). They need other things to provide them with scaling to multiple block devices and there is no block device level substitute for supporting tiered storage at the filesystem level.

That said, ZFS has a killer feature that ext4 and XFS do not have, which is low cost replication. You can snapshot and send/recv without affecting system performance very much, so even in situations where ZFS is not at the top in every benchmark such as being on equal hardware, it still wins, since the performance penalty of database backups on ext4 and XFS is huge.

Re: ZFS 2.3 released with ZFS raidz expansion

#254

Post by p_l » Tue, Jan 14, 2025, 9:50 PM UTC

GeorgeTirebiter wrote: post #246

snvzz wrote: post #20

Earlier quoted context omitted.

The fifth is also, once you consider non-ascii names.

Could someone show a legit reason to use 1000-character filenames? Seems to me, when filenames are long like that, they are actually capturing several KEYS that can be easily searched via ls & re's. e.g. 2025-Jan-14-1258.93743_Experiment-2345_Gas-Flow-375.3_etc_etc.dat But to me this stuff should be in metadata. It's just that we don't have great tools for grepping the metadata. Heck, the original Macintosh FS had no…

> Could someone show a legit reason to use 1000-character filenames?

1023 byte names can mean less than 250 characters due to use of unicode and utf-8. Add to it unicode normalization which might "expand" some characters into two or more combining characters, deliberate use of combining characters, emoji, rare characters, and you might end up with many "characters" taking more than 4 bytes. A single "country flag" character will be usually 8 bytes, usually most emoji will be at least 4 bytes, skin tone modifiers will add 4 bytes, etc.

this ' ' takes 27 bytes in my terminal, '󠁧󠁢󠁳󠁣󠁴󠁿' takes 28, another combo I found is 35 bytes.

And that's on top of just getting a long title using let's say one of CJK or other less common scripts - an early manuscript of somewhat successful Japanese novel has a non-normalized filename of 119 byte, and it's nowhere close to actually long titles, something that someone might reasonably have on disk. A random find on the internet easily points to a book title that takes over 300 bytes in non-normalized utf8.

P.S. proper title of "Robinson Crusoe" if used as filename takes at least 395 bytes...

Re: ZFS 2.3 released with ZFS raidz expansion

#255

Post by curt15 » Tue, Jan 14, 2025, 10:11 PM UTC

jeltz wrote: post #242

lousken wrote: post #74

Earlier quoted context omitted.

as far as stability goes, btrfs is used by meta, synology and many others, so I wouldn't say it's not stable, but some features are lacking

It is possible to corrupt the file system from user space as a normal user with Btrfs. The PostgreSQL devs found that when working on async IO. And as fer as I know that issue has not been fixed. https://www.postgresql.org/message-id/CA%2BhUKGL-sZrfwcdme8j...

LMDB users also unearthed a btrfs data corruption bug last year: https://bugzilla.redhat.com/show_bug.cgi?id=2169947

Re: ZFS 2.3 released with ZFS raidz expansion

#256

Post by ryao » Tue, Jan 14, 2025, 10:13 PM UTC

pimeys wrote: post #114

whataguy wrote: post #113

Earlier quoted context omitted.

The difference is that the ZFS kernel module is included by default with Proxmox, whereas with e.g. Debian, you would need to install it manually.

And you can't follow the latest kernel before the ZFS module supports it.

There is a trick for this:

  * Step 1: Make friends with a ZFS developer.
  * Step 2: Guilt him into writing patches to add support as soon as a new kernel is released.
  * Step 3: Enjoy

Adding support for a new kernel release to ZFS is usually only a few hours of work. I have done it in the past more than a dozen times.

Re: ZFS 2.3 released with ZFS raidz expansion

#257

Post by p_l » Tue, Jan 14, 2025, 10:24 PM UTC

p_l wrote: post #254

GeorgeTirebiter wrote: post #246

Earlier quoted context omitted.

Could someone show a legit reason to use 1000-character filenames? Seems to me, when filenames are long like that, they are actually capturing several KEYS that can be easily searched via ls & re's. e.g. 2025-Jan-14-1258.93743_Experiment-2345_Gas-Flow-375.3_etc_etc.dat But to me this stuff should be in metadata. It's just that we don't have great tools for grepping the metadata. Heck, the original Macintosh FS had no…

> Could someone show a legit reason to use 1000-character filenames? 1023 byte names can mean less than 250 characters due to use of unicode and utf-8. Add to it unicode normalization which might "expand" some characters into two or more combining characters, deliberate use of combining characters, emoji, rare characters, and you might end up with many "characters" taking more than 4 bytes. A single "country flag" ch…

hah. Apparently HN eradicated the carefully pasted complex unicode emojis.

The first was "man+woman kissing" with skin tone modifier, then there was few flags

Re: ZFS 2.3 released with ZFS raidz expansion

#258

Post by ryao » Tue, Jan 14, 2025, 10:28 PM UTC

bayindirh wrote: post #236

ryao wrote: post #234

Earlier quoted context omitted.

ZFS will outscale ext4 in parallel workloads with ease. XFS will often scale better than ext4, but if you use L2ARC and SLOG devices, it is no contest. On top of that, you can use compression for an additional boost. You might also find ZFS outperforms both of them in read workloads on single disks where ARC minimizes cold cache effects. When I began using ZFS for my rootfs, I noticed my desktop environment became mo…

No doubt. I want to reiterate my point. Citing myself: > "I personally won't use either on a single disk system as root FS , regardless of how fast my storage subsystem is." (emphasis mine) We are no strangers to filesystems. I personally benchmarked a ZFS7320 extensively, writing a characterization report, plus we have a ZFS7420 for a very long time, complete with separate log SSDs for read and write on every box. H…

I am generally happy with the write performance of ZFS. I have not noticed slow system updates on ZFS (although I run Gentoo, so slow is relative here). In what ways is the write performance bad?

I am one of the OpenZFS contributors (although I am less active as late). If you bring some deficiency to my attention, there is a chance I might spend the time needed to improve upon it.

By the way, ZFS limits the outstanding IO queue depth to try to keep latencies down as a type of QoS, but you can tune it to allow larger IO queue depths, which should improve write performance. If your issue is related to that, it is an area that is known to be able to use improvement in certain situations:

https://openzfs.github.io/openzfs-docs/Performance%20and%20T...

Re: ZFS 2.3 released with ZFS raidz expansion

#259

Post by honestSysAdmin » Tue, Jan 14, 2025, 10:32 PM UTC

GuB-42 wrote: post #73

poisonborz wrote: post #59

I just don't get it how the Windows world - by far the largest PC platform per userbase - still doesn't have any answer to ZFS. Microsoft had WinFS and then ReFS but it's on the backburner and while there is active development (Win11 ships some bits time to time) release is nowhere in sight. There are some lone warriors trying the giant task of creating a ZFS compatibility layer with some projects, but they are far f…

To be honest, the situation with Linux is barely better. ZFS has license issues with Linux, preventing full integration, and Btrfs is 15 years in the making and still doesn't match ZFS in features and stability. Most Linux distros still use ext4 by default, which is 19 years old, but ext4 is little more than a series of extensions on top of ext2, which is the same age as NTFS. In all fairness, there are few OS compon…

  https://openzfs.github.io/openzfs-docs/Getting%20Started/index.html

ZFS runs on all major Linux distros, the source is compiled locally and there is no meaningful license problem. In datacenter and "enterprise" environments we compile ZFS "statically" with other kernel modules all the time.

For over six years now, there is an "experimental" option presented by the graphical Ubuntu installer to install the root filesystem on ZFS. Almost everyone I personally know (just my anecdote) chooses this "experimental" option. There has been an occasion here and there of ZFS snapshots taking up too much space, but other than this there have not been any problems.

I statically compile ZFS into a kernel that intentionally does not support loading modules on some of my personal laptops. My experience has been great, others' mileage may (certainly will) vary.

Re: ZFS 2.3 released with ZFS raidz expansion

#260

Post by bmicraft » Tue, Jan 14, 2025, 10:39 PM UTC

ryao wrote: post #62

endorphine wrote: post #25

Can someone describe why they would use ZFS (or similar) for home usage?

To give an answer that nobody else has given, ZFS is great for storing Steam games. Set recordsize=1M and compression=zstd and you can often store about 33% more games in the same space. A friend uses ZFS to store his Steam games on a couple of hard drives. He gave ZFS a SSD to use as L2ARC. ZFS automatically caches the games he likes to run on the SSD so that they load quickly. If he changes which games he likes to…

As I understand, L2ARC doesn't work across reboots which unfortunately makes it almost useless for systems that get rebooted regularly, like desktops.