Btrfs Gets Talked Up, Googler Encourages You To Try Btrfs

[jeff_g]

The primary reasons given in the talk (he seemed to stress it more than the slides make it seem) was regarding snapshots and the ability to send those snapshots to remote systems. Slide 35 and 36 actually explain something I've done (2.5 ssd to msata though) as a fall back method for whenever I manage to really bork up my laptop and suddenly need it usable for something.

I was sure it was going to be a full on flame war by now. ZFS does have plenty of die hard fans.

It almost did at the presentation. Some guy in the front row started listing "factual errors" in Marc's statements regarding ZFS legal details and just refused to drop it until after Chris spoke up.

I'm using btrfs for my home directory now, but I have noticed that sometimes there are some odd bugs or hangs. For example, on my laptop running linux 3.16 the moment the partition is full the system becomes so unresponsive that I have to SysRq reboot it. Then afterwards some files are missing, and as usual the chrome preferences are corrupted...

Marc and Chris were discussing this after the talk actually - are you using Laptop Mode Tools and/or aggressive power saving tweaks? I think Marc said he put in a bug report for it or was going to. I've encountered similar issues, but I thought I had done something to break it and so didn't dig very deep into it.

[drSeehas]

... ZFS license ...

It is not a "ZFS" license, it is the CDDL.

... is one huge pile of dung.

Why? It is an approved open source license.
OpenSolaris (itself CDDLd) and the BSDs have no problem with the CDDL.
As far as I understand, the GPL is not compatible with the CDDL.
So I think, Linux has the wrong license and should change it if possible.

[drSeehas]

Because you cannot distribute ZFS with the kernel with its current license?

I know, but what is the problem with not distributing ZFS with the kernel?

[brosis]

WHY would they want to reimplement ZFS when it is open source?

Not only they can?t distribute with kernel, they can?t integrate properly, reach proper speeds, memory efficiency, boot from it at least. ZFS license is one huge pile of dung.

[erendorn]

WHY would they want to reimplement ZFS when it is open source?

Because you cannot distribute ZFS with the kernel with its current license?

[drSeehas]

... What i meant was that linux devs can't reimplement ZFS from scratch ...

WHY would they want to reimplement ZFS when it is open source?

[nils_]

I'm using btrfs for my home directory now, but I have noticed that sometimes there are some odd bugs or hangs. For example, on my laptop running linux 3.16 the moment the partition is full the system becomes so unresponsive that I have to SysRq reboot it. Then afterwards some files are missing, and as usual the chrome preferences are corrupted...

[nils_]

ZFS is heavily patented, but my understanding is that Sun pledged not to sue anyone using a CDDL-licensed codebase. That's why they can't just reimplement it and stick it into the linux kernel, where it would be GPL2 code and invite patent lawsuits.

And Sun doesn't really exist anymore as a company (I made a nice bundle when ORCL bought them).

[dunovan]

Except within 3.14-2-amd64

INFO: task btrfs-transacti:1006 blocked for more than 120 seconds.
Tainted: G O 3.14-2-amd64 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
btrfs-transacti D ffff8807fc696528 0 1006 2 0x00000000
ffff8807fc696110 0000000000000046 0000000000014380 ffff8800d38a5fd8
0000000000014380 ffff8807fc696110 ffff88081fa94c10 ffff88081fdb7388
0000000000000002 ffffffff81121280 ffff8800d38a5ad0 ffff8800d38a5bb8
[347545.451908] Call Trace:
[<ffffffff81121280>] ? wait_on_page_read+0x60/0x60
[<ffffffff814c8284>] ? io_schedule+0x94/0x130
[<ffffffff81121285>] ? sleep_on_page+0x5/0x10
[<ffffffff814c85f4>] ? __wait_on_bit+0x54/0x80
[<ffffffff8112108f>] ? wait_on_page_bit+0x7f/0x90
[<ffffffff8109f5a0>] ? autoremove_wake_function+0x30/0x30
[<ffffffff8112e128>] ? pagevec_lookup_tag+0x18/0x20
[<ffffffff81121170>] ? filemap_fdatawait_range+0xd0/0x160
[<ffffffffa01f8ea5>] ? btrfs_wait_ordered_range+0x65/0x120 [btrfs]
[<ffffffffa021f43e>] ? __btrfs_write_out_cache+0x6fe/0x8f0 [btrfs]
[<ffffffffa021f909>] ? btrfs_write_out_cache+0x99/0xd0 [btrfs]
[<ffffffffa01d0fde>] ? btrfs_write_dirty_block_groups+0x58e/0x680 [btrfs]
[<ffffffffa024b53d>] ? commit_cowonly_roots+0x14b/0x202 [btrfs]
[<ffffffffa01e058a>] ? btrfs_commit_transaction+0x42a/0x990 [btrfs]
[<ffffffffa01e0b7b>] ? start_transaction+0x8b/0x550 [btrfs]
[<ffffffffa01dc3dd>] ? transaction_kthread+0x1ad/0x240 [btrfs]
[<ffffffffa01dc230>] ? btrfs_cleanup_transaction+0x510/0x510 [btrfs]
[<ffffffff81080af8>] ? kthread+0xb8/0xd0
[<ffffffff81080a40>] ? kthread_create_on_node+0x170/0x170
[<ffffffff814d308c>] ? ret_from_fork+0x7c/0xb0
[<ffffffff81080a40>] ? kthread_create_on_node+0x170/0x170

[smitty3268]

ZFS code is CDDL, using it on another OS can't change that. It is also CDDL in FreeBSD. However unlike the BSD license, which allows parts of the kernel to use a different license (CDDL), the GPL2 does not. This is why it cannot be included in Linux, but then again, the whole point of the CDDL is precisely to be a nuisance for Linux.

Sun's ZFS code is CDDL. What i meant was that linux devs can't reimplement ZFS from scratch using the specs (or reverse engineer it) as GPL code, because then they'd be sued for patent infringement.