Btrfs on root fs

Has someone tried to change the root Filesystem to btrfs? Did it work? Does it worth it?

I’m planning to try/test it on a separate sd card that I have. Just checking if someone had any experience or info to share about it

What benefits do you expect from changing to Btrfs other than having the option of doing snapshots?

Creating snapshots and checksum - “error on silent file corruption” (that happened at least twice in the past year and a half)

It’s not recommended storing /boot or / on btrfs. Ext2 would be my choice, it’s the fastest and who needs journaling really?

As for /storage, btrfs would be a good option, just not /boot.

The /boot partition on a Raspberry Pi must be vfat, otherwise the GPU cannot boot the system.

Are you for real ? ext4 is not “just” ext2 with journalling. There are so many limitations in ext2 by modern day standards that nobody would seriously suggest it. It is possible to turn off journalling in ext4 by the way.

Are you sure you weren’t looking for the OpenElec forum ? No /storage here… :slight_smile:

No silent file system corruption here on my Pi’s in the time since I’ve been working on OSMC. If you’re getting silent file system corruption you should be trying to resolve any underlying hardware problems first.

While I don’t disagree with a consistency checking file system in general (such as ZFS) I would point out that the vast majority of PC’s also run on file systems that do not checksum or integrity check user data - and somehow we have got by these last few decades just fine.

If you were to attempt to change the root file system you would also have to rewrite the initramfs in the kernel to know how to deal with other file systems during the fsck check and initial mounting:

After a bad experience with f2fs a couple of years ago we’re likely to stay with ext4 for the foreseeable future. It performs well enough and is the most widely supported Linux file system, which is useful when trying to access the data from another machine during recovery etc.

You also need to keep in mind that some OSMC hardware platforms run very different kernel versions - for example the Vero 2 runs Linux 3.10.94 at the moment - how is the btrfs support in that ?

[quote=“DBMandrake, post:5, topic:14761”]
Are you for real ? [/quote]

Ext2 has better latency and write performance over Ext4. Exactly the things that matter on Pi.

So OSMC is UEFI, I didn’t know that and apologies for using the wrong directory, but you knew what I meant.

And yes, I am old school. I’ve been using Linux since '99.

And Ext2 is optimised with flash based disks like SD cards in mind ? I don’t think so… Ext2 does not even support discard/trim, which is pretty important on some devices. (Vero 2 at the moment for OSMC, but x64 later)

OSMC is not UEFI - Raspberry Pi’s and Vero’s don’t use UEFI. They each have their own boot loading process. The Vero’s use uboot while the Pi has its own custom GPU bootloader system that is not like anything else out there.

/storage is an OpenElec thing.

Same here, using Linux since the mid 90’s. I took a leave of absence in the mid 2000’s and by the time I came back into the fold I realised that a lot has changed in the Linux world since then such that I had to catch up. File systems is one of them.

Xbian uses BTRFS, but in my experience before I switched to OSMC it was definitely not more stable.
Also, the initiative from XBian to try BTRFS came from many SD card corruption issues, which were I believe all related to different causes like bad power supply etc.
I have never experienced SD card corruption and I did a lot of testing in the past on different RPI1 and RPI2 configurations.

Actually, this is the part that I want to understand. The Filesystem conversion, changing the mount parameters to btrfs, etc are all fine.

How to rewrite initramfs? Osmc kernel supports btrfs already, right?

Dude seriously, we have a difference of an opinion. It’s real nice to join a forum, hang around for a day and get
condescending replies from a developer about a subject that bears no meaning. I literally was saying what I would do, you can do stuff differently.

Nice welcome.

Not being condescending here - just bringing you up to speed on such misapprehensions as:

a) The /boot partition can’t be anything other than vfat for a Pi

b) Ext2 was not written with flash media in mind (no discard support for one) so any performance comparison made on a spinning disk is irrelevant for devices that boot from flash such as all current OSMC devices. We need discard support for some devices (Vero 2 and x64) and that was only added in ext4 so earlier versions of ext need not apply.

You’re welcome to hold opinions on such matters but it doesn’t change the facts. We won’t be switching to ext2 any time soon.

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I have all my media stored on an external drive connected to my Pi that is btrfs and have noticed that it seems to mount/unmount slowly. It’s a 4TB drive. Since I so rarely reboot, i’ve never bothered to try and figure out why it seems slow to mount/unmount. The reason I chose btrfs was I’m planing on picking up another 4TB drive and mirroring it.

But with the slow mount in mind, btrfs may not be a good idea for /

You just don’t get it. I’m not telling you to change anything.

How are the phrases “my choice” or “what I would do” not translating to you? I’m not suggesting you change anything, I’m not even telling you how it should be done. I’m telling you what I would do. I have no idea how me telling you that I use ext2 on small partitions like /boot and / turned into this stupid flame war.

It’s good for recovery to use partitions that can be accessed with just about anything. /boot is generally less than 256M and / contains only the directories and maybe basic libs & binaries. ZFS would be my choice overall, but I wasn’t talking about that here. Just how I would personally do things in general, oh and I’m not suggesting.

Not being condescending here

Phares like these kinda sound like that:

Are you for real ?
by modern day standards that nobody would seriously suggest it
I don’t think so… Ext2 does not even
just bringing you up to speed?
hold opinions on such matters but it doesn’t change the facts

Absolutely no condescension there apparently.

We won’t be switching to ext2 any time soon.

At which point I suggested this?

Don’t worry, you won’t be seeing me anymore with my silly ideas, I’m back with Arch.

The Pi requires a FAT partition for booting. What is good about FAT, is that Linux, OS X and Windows users can easily change key files (kernel, bootloader or config.txt) if things go wrong. This is particularly useful for the overclockers who may push the Pi a little too hard and not have a Linux system to mount the SD card.

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Sorry but you’re being way too sensitive to a little bit of criticism on a couple of technical points. You wouldn’t last 5 minutes over at with that kind of thin skin.

I’m also not sure how the conversation escalated so far, to me it seems like you made a couple of ill considered comments such as “who needs journaling really?” and then wondered why someone took issue with your comments.

Yes we do want journalling, and ext4 with its discard support and other modern features. You are most welcome to stick to ext2 on your (presumably) spinning disks.

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