
File Systems – ZFS vs. XFS - truth_seeker
https://linuxhint.com/zfs_vs_xfs/
======
psankar
> One last point of architectural difference is this — XFS has B+ tree
> implementation for searching files and allocating space. This makes
> searching and fetching the data much faster. OpenZFS has no such feature.

I wish I could downvote this article, just for this one point alone. I wonder
what kind of benchmarking the author did to come to the conclusion of
"searching and fetching the data much faster" and how much the B+ tree of xfs
contributed to it. Speed depends on a lot of factors (copy on write,
compression, journaling, crash recovery, etc.) and I wonder how the author
narrowed it down to the B+ tree of XFS. Also, there could be variants of
various B family trees even within a same filesystem. So I am not really sure,
what the author means by "XFS has B+ tree implementation".

If you are a RedHat shop and deploy linux extensively already, then xfs may be
a better option, if you are not looking for most zfs features like volume
management, etc. Also, installation, support etc. would be much easier.

This article is shallow in many ways technically, but arrives at conclusions
strongly. It just seems like a paid article to promote zfs.

May be an article on LWN would be more meaningful and technically competent to
make a comparison than this.

~~~
theamk
It looks to me like this was an attempt to make XFS look better? The author
probably looks at the things from "the reliability is #1, and the rest is
secondary" standpoint, so they are having a hard time coming with pro-XFS
arguments.

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buster
I was expecting some more technical proof, benchmarks or similar. Sadly, this
post reads as a pure advertisement piece to use OpenZFS.

What should i take away in this sentence? "XFS is optimized for huge files and
for parallel I/O this makes it the easier choice for use cases like NASA
Advanced Supercomputing Division." The whole post sounds like "ZFS is the
superior technology with much more bells and whistles and XFS is old tech but
XFS is what you choose if you're the NASA..".

Having interest in XFS/ZFS/BTRFS and what to choose on my machines, i was
hoping for some more substantial and objective facts.

~~~
truth_seeker
It might not what exactly you are looking for, but i think it's close.

MySQL performance bench suite against ZFS vs XFS

[https://www.percona.com/blog/2018/05/15/about-zfs-
performanc...](https://www.percona.com/blog/2018/05/15/about-zfs-performance/)

------
noodlesUK
I don’t really know that this is a particularly appropriate comparison. XFS is
a fine filesystem, but ZFS is more than a filesystem, it’s RAID, LVM,
deduplication, etc. The real competitors to ZFS from my understanding are
largely BTRFS and proprietary technologies such as apple’s new APFS. I’d very
much like to see a comparison between those. I’ve run ZFS on my systems for
years, but moved away from it towards btrfs on my laptop, as it was just too
much pain to keep the kernel modules up to date. I wish the CDDL were
compatible with the GPL, cause if the drivers were in-tree there wouldn’t be
any argument at all.

~~~
josteink
With Ubuntu you get binary modules updated together with the kernel.

I moved the opposite direction (btrfs->zfs) because I had issues with my main
btrfs rootfs constantly degrading to read-only mode, causing my system to
crash and require rebooting.

With ZFS I’ve had no such issues. ZFS uses noticeably much more RAM though.

~~~
noodlesUK
Yeah, I was on Gentoo at the time, which didn’t make it particularly difficult
(when everything is source code it doesn’t really matter), but I’m on Fedora
now, where the story is a bit different. Ubuntu shipping the binary modules is
good. Do they support booting from ZFS simply (that is, are the kernel modules
in the initramfs)?

~~~
josteink
Yeah. All my systems are pure ZFS systems.

The initial install is a bit involved (live-cd, manual partitioning +
debootstrap) but everything just works (tm) after that, including booting into
specific snapshots from grub.

There’s a good guide on github:

[https://github.com/zfsonlinux/zfs/wiki/Ubuntu-18.04-Root-
on-...](https://github.com/zfsonlinux/zfs/wiki/Ubuntu-18.04-Root-on-ZFS)

------
nineteen999
> XFS is largely supported on Linux along with IRIX

Use of the present tense regarding IRIX here made me chuckle. The last version
of IRIX is 6.5.30, released in August 2006.

~~~
lallysingh
And by that point, there wasn't much going on in Irix development. 6.5 was out
in the late 1990s, IIRC.

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DiabloD3
This article is mildly ironic to me: I use XFS for my boot file system, a
small 16GB in an mdraid mirror, to boot my ZFS server.

They are both useful, and the ultimate solution, for different cases. BTRFS
has no future, and ext4 is purely a legacy solution (also ironic, given XFS is
older than ext4).

~~~
muxator
Btrfs is actively developed, and stable for the cases indicated in
[https://btrfs.wiki.kernel.org/index.php/Status](https://btrfs.wiki.kernel.org/index.php/Status)
.

The mailing list gives interesting insights on what the developers are working
on.

~~~
Fnoord
Seems actively developed indeed: [1]. The current contributors are Facebook,
Fujitsu, SUSE, and Oracle.

Its XFS which never had a future because it lacks features which modern
filesystems have. Adding these features would be akin to making a new
filesystem (which could contain the acronym XFS).

The only real (integrity) issue BTRFS currently has is write hole in RAID5/6\.
Its a long standing issue...

[1]
[https://btrfs.wiki.kernel.org/index.php/Contributors](https://btrfs.wiki.kernel.org/index.php/Contributors)

~~~
viraptor
It's not true that this is the only issue unfortunately. As much as I want
btrfs to succeed, I've seen it disappear completely from my drives and it does
have quite a few crashing bugs:
[https://bugzilla.kernel.org/buglist.cgi?bug_status=NEW&bug_s...](https://bugzilla.kernel.org/buglist.cgi?bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&component=btrfs)

I want it to be stable and safe already, but realistically, we still need to
wait.

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gdfasfklshg4
Should a fair comparison not include the features of LVM etc that Red Hat etc
are layering together with XFS?

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ofrzeta
I don't know about ZFS but you can't shrink XFS filesystems (opposed to
Ext3/4). It may not be the most common use case but I tend to forget about it,
used XFS as the fs and then got into problems because of that non-feature.

[http://xfs.org/index.php/Shrinking_Support](http://xfs.org/index.php/Shrinking_Support)

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hnlmorg
On the topic of ZFS on Linux, does anyone know the expected timeline for
version 8 of ZoL? Or is it just a case of "it will be ready when it's ready"?

I've had to import an pool from FreeBSD but can only mount the volume as
readonly because of a feature flag enabled that isn't in v7 but is currently
in the RC versions of 8. I'm a little nervous about running the RC versions
because this is a "production" pool (albeit just a home server).

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fsiefken
I/O on ZFS might be faster if you turn on compression at the expense of memory
and cpu. XFS has no such feature, BTRFS has though.

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mikece
"For the sake of clarity, when we say ZFS we mean OpenZFS and not the
commercial version supported by Oracle Inc."

Just curious: what are the differences between [Oracle] ZFS and OpenZFS?

~~~
georgyo
At this point, the list is very long. Development forked many years ago when
Oracle closed the source. Both sides have been in very active development
since.

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lasermike026
Doesn't ZFS consume more resources?

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tinus_hn
Wow, I thought XFS was dead but apparently it is still supported.

~~~
gdfasfklshg4
It is the FS for Red Hat 7 and CentOS 7.

~~~
Tepix
Also on RHEL 8.

XFS gains the XFS Copy-On-Write Data Extents feature in RHEL 8 which can speed
things up and save space.

