Approved: Fedora 33 Desktop Variants Defaulting To Btrfs File-System

[pal666]

: face palm :

ZFS does the same thing. I wonder where BTRFS got the idea. heh..

so zfs has same thing but with excessive memory usage. ok

[pal666]

??? So what you are saying is.. if I format my disk with BTRFS, and then I smash it to bits with a hammer.. BTRFS still has my files?

no, that's your imagination. what i'm saying is bitrot happens on single devices too and extra copy with scrub will autoheal

[k1e0x]

No, I only want to say that what btrfs does is still "online deduplication" and you should really stop moving goalposts.

I run ZFS in my KVM server (VMs virtual drives are vdevs, all managed by libvirt/Virt Manager), and I did try dedupe, yes. It's an overrated feature, not for ZFS issues mind me, it's just that deduplication in general is amazing at some specific niche cases and very meh at most other cases. I really don't have dozens of same-y VMs with just a few changes, so it's mostly useless for me.

I would rather have a defrag tool, like btrfs has, and not having to rely on send/receive (to another filesystem and back) to "defrag" a vdev.

Should try it the other way around. ZVOL's make excellent vm disks. (a lot better than qcow, qcow2, etc) it's also supported in libvirt but in virt-manager there is a bug that detects the datasets incorrectly and you have to manually specify the path.. (/dev/zvol/pool/dataset/disk) otherwise it works good.

The dedup in ZFS now really isn't so hot. It's mostly useful for maybe similar blocks on a VM cluster or a directory full of hash files, other than that.. mmm.. It loads that entire bitmap into ram right now and it does so forever. Keep in mind that everything ZFS does is based on blocks, not files so dedup works on blocks.. there are some advantages to that (such as VM's) but it isn't what a lot of end users expect. I would caution ppl know exactly what they are doing before using it. I would expect the new version to be maybe a year or two out. (if ZFS encryption implementation timeline is an example.. big project and lot of work and it took about 2 years for us to get that.)

[kloczek]

I would rather have a defrag tool, like btrfs has, and not having to rely on send/receive (to another filesystem and back) to "defrag" a vdev.

Deftragmentation is completly not needed.
ZFS uses SLAB allocator which prevents fragmentation.
On Linux SLAB allocator is used in memory management. Did you heard that someone is doing "RAM defrgmentation" on Linux?

[kloczek]

it isn't out of date for them. There are some different flags added in OpenZFS tho. (such as -p and -v everywhere) and sure.. there are lots of features in OpenSolaris that Oracle doesn't have. Sometimes they implemented them differently too. Off the top of my head.. the checkpoint and bookmark feature I mentioned before isn't in Oracle and I don't think they have Compressed ARC or the or Async destroy, or resilver defer The encryption model is also different (broken) in Oracle.

Correction: OK.so which ale Solaris ZFS fearures are oudated in OpenZFS?
You are wrong about comressed ARC. Oracle ZFS had compressed ARC way before OpenZFS, It has been done before set changes calles "ReARC" which was introduced in 2014.

[pal666]

Try to find something like that on any Linux FS

btrfs balance start -dconvert=dup /mnt
moron, btrfs supported it from the start, zfs added it in 2010

[starshipeleven]

So you want to say

No, I only want to say that what btrfs does is still "online deduplication" and you should really stop moving goalposts.

don't need to run any commands to perform deduplication?

I run ZFS in my KVM server (VMs virtual drives are vdevs, all managed by libvirt/Virt Manager), and I did try dedupe, yes. It's an overrated feature, not for ZFS issues mind me, it's just that deduplication in general is amazing at some specific niche cases and very meh at most other cases. I really don't have dozens of same-y VMs with just a few changes, so it's mostly useless for me.

I would rather have a defrag tool, like btrfs has, and not having to rely on send/receive (to another filesystem and back) to "defrag" a vdev.

[k1e0x]

OK so which one feature OpenZFS has which Oracle Solaris ZFS dosn't?
Can you point on any Solaris documentation which is out-of-date?

it isn't out of date for them. But it dosen't include new info for OpenZFS. There are some different flags added in. (such as -n and -v everywhere) and sure.. there are lots of features in OpenZFS that Oracle doesn't have. Sometimes they implemented them differently too. Off the top of my head.. the checkpoint and bookmark features I mentioned before isn't in Oracle and I don't think they have Compressed ARC or the or Async destroy, or resilver defer The encryption model is also different (broken) in Oracle. There are some big dev features coming such as Persistent L2ARC, ZFS reflow to resize raid-z, and the dedup fix.

Generally I think they try to keep things the same but the fork happened over 10 years ago.. i'd be kind of curious to see if Solaris 11.4 could import a pool made on FreeBSD or illumos. I highly doubt it. Almost for sure ZoL's would choke even with all the flags off. They are just different things now.. like MariaDB and MySQL. (ironically also due to Oracle's take over)

[kloczek]

Hey one thing I've noticed. Don't link to the Oracle docs, because they are often out of date or just wrong or don't have the features of OpenZFS. If you're doing a search try adding "ZFS FreeBSD" to it - Usually that gives good, up to date and proper docs for OpenZFS.

The Oracle docs are all over and they are not always right.

OK so which one feature OpenZFS has which Oracle Solaris ZFS dosn't?
Can you point on any Solaris documentation which is out-of-date?

[kloczek]

I guess when I run duperemove on my mounted btrfs it's just lying to me. Is it all in my head, none of this is real, right? (it should also work on xfs, never used it on xfs though)
https://github.com/markfasheh/duperemove

Here the btrfs wiki also explains more and lists some other tools to do that on a MOUNTED btrfs https://btrfs.wiki.kernel.org/index.php/Deduplication

So you want to say that you don't know that with zfs you don't need to run any commands to perform deduplication?