Btrfs To Ship Multiple Performance Improvements In The Next Linux Kernel

[ChrisIrwin]

write script which does chattr +C ? how btrfs should know which files are "bad for cow" and "not needed to snapshot" at the same time?

Setting +C doesn't disable snapshots. You can still snapshot files that you've disabled COW on, and BTRFS will handle that by silently doing COW on your +C files while the snapshot exists.

[jacob]

(1)By the same token, it cannot migrate to, lets say, GPLv3

Indeed. But that's OK. I have never been been fond of that "or any later version" clause. I also release my own software strictly as GPLv2 only. In part because I still can't wrap my mind about what the GPLv3 actually means in terms of its legal foundations and consequences, and also because I don't like the idea that someone will at some point rewrite the licence for my software in ways that I can't predict.

(2)Bunch of random incidents aided Linux equally or more than it's license. Linux took off in popularity when FreeBSD was implementing SMP and did at first shitty job. Then FreeBSD's users (it was used far more than Linux back then) migrated to Linux because it happened to be ready and accessible alternative (no OpenSolaris yet). Later times, additional factors aiding Linux were Oracle closing OpenSolaris after buying Sun and Google opting to use Linux kernel for it's new embedded OS Android. Without all of it, FreeBSD or OpenSolaris could easily be in the same position Linux has nowadays. Just mostly luck IMHO.

Of course everything can always be attributed to luck, but initially FreeBSD was really more advanced than Linux, and yet the big players preferred investing massively into then-toy OS Linux (in the case of IBM, it was literally billions of $$$) than contributing to FreeBSD which, in theory, could have been ready for prime time quicker and for cheaper thanks to its headstart. One can forever speculate why it was so, but FWIW my explanation is that contributing stuff like XFS, LVM, RCU etc. to BSD means effectively giving it for free to your competitors to use in their proprietary products, that compete directly with your own. Contributing the same to Linux is safe from this point of view, courtesy to the copyleft a.k.a. viral nature of the GPL.

Where GPL in fact aided and served it's purpose was with Linksys court case - suddenly people could have access to sources for their routers - would not have been possible with BSD license.

That was great for the users of those routers. In terms of the importance of the GPL for Linux's fate it's a footnote.

Also, define success - Linux has a few percents market on desktop and still less far smaller market share in servers than Windows, except for web servers where it indeed rules the roost.

The desktop remains the great failure for Linux, that's clear. As for the rest, which planet do you live on? Windows holds something like 35% of the overall server market and is heavily concentrated mainly on SMBs. The rest is pretty much all Linux (with a very very VERY few notable exceptions). And there is also a lot more to computing than desktop and servers. Last time I looked it up (~ 2 weeks ago), some 67% of all cloud deployments were Linux-based. All 500 of the current Top500 run Linux. More than 75% of all mobile devices in the world run Linux. In the IoT world, there is basically Arduino, MIPS and ARM, and the latter two are virtually all Linux (if you search hard enough you may be able to find the odd NetBSD here or there, but it's statistically irrelevant).

That's a definition of success lots of people would dream of.

[pcxmac]

those people are idiots. btrfs is stable, zfs on linux is outoftree not supported piece of shit

Lol. I have to say I have lost a lot more bytes to ZFS than BTRFS. But I do use ZFS for spinning rust/big storage. Last time I tried doing anything interesting with python and BTRFS I found the sysfs organization/offering to be lacking to say the least.

[Zan Lynx]

Is btrfs stable for daily use? I see people regularly mention that ZFS should be used for critical data and btrfs is still a toy...

I've been using it since 2012. I started with two 2 TB drives in RAID-1. Then I added two more 6 TB drives. Then a couple of 4 TB drives which were on sale. Then a 2 TB drive developed some weird bad blocks. Weird because they reported read errors but direct writes to those blocks did not report errors, but then the read blocks would eventually return errors again. And SMART didn't report any block remapping. So I trashed both 2 TB drives and replaced them with 6 TB drives.

During all of this I used btrfs to convert from RAID-1 to RAID-10 and to migrate the array to the new drives as they arrived.

I've had a couple of problems but nothing that a scrub and balance couldn't fix. It helped a lot that I run Fedora and wasn't stuck with some weird half-patched and ancient CentOS or Debian kernel.

[ElectricPrism]

I'd like to start a running joke that Linux 4.20 was so incredibly good that everyone time warped to Linux 5.0 and forgot Linux 4.21+ assuming 4.20 is 5.0.

[waxhead]

Is there automatic way of disabling CoW on “bad to CoW” files like VMs or bittorrent?

chattr +C /path/to/some/file/or/directory

You make the directory NoCow and all *new* files created in that directory will not be COW'ed

[Nille]

if you are working in a professional setting you might want to consider spending more and mirroring / load balancing. Probably use ZFS too.

More is not possible.

There are really any number of factors which affect which file system you use. Having to rebuild a RAID array while it is operational can be a little taxing.

But for this we do have raid. If a Disk is failing wen can simply replace it and rebuild the raid while operating.

As for LVM, lulz. Hate it with a passion, no need for it when you have file systems like ZFS or BTRFS, and MDADM is good enough anyways. LVM on the commandline = puke.

Thats was just sarcastic. if i have to do a full restore from backup after each disk failure the point in raid is then useless.

[Spazturtle]

Im talking without user intervention

Submit a patch to your torrent client that adds an option to auto add the 'nodatacow' flag to any file it creates?

[curfew]

chattr +C /path/to/some/file/or/directory

You make the directory NoCow and all *new* files created in that directory will not be COW'ed

Congratulations! You're the third guy to answer and completely fail to understand the meaning of AUTOMATIC. Automation is the complete opposite of having to manage everything by hand. OP did not ask how to disable COW, he asked how to make it automatic. Implying he already knew how to do it manually.

Submit a patch to your torrent client that adds an option to auto add the 'nodatacow' flag to any file it creates?

That's just retarded. Obviously there's no sense patching every single app that works with files to support a filesystem-level feature. It has to be a system service at a bare minimum if it cannot be built into the kernel.

[ssokolow]

and also because I don't like the idea that someone will at some point rewrite the licence for my software in ways that I can't predict.

The GPLv3 allows projects to defer the "or a later version" decision by specifying a person who will be responsible for ruling on whether it applies once they've had a chance to actually see it.

Here's one mention of that:

If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Program.