[linux-lvm] Does LVM have any plan/schedule to support btrfs in fsadm

heming.zhao at suse.com heming.zhao at suse.com
Sun Jun 27 17:40:46 UTC 2021

On 6/25/21 6:57 PM, Zdenek Kabelac wrote:
> Dne 25. 06. 21 v 7:28 heming.zhao at suse.com napsal(a):
>> Hello Zdenek & David,
>> From URL: https://fedoraproject.org/wiki/Btrfs
>> The btrfs becomes default filesystem for desktops.
>> Do we have any plan to add btrfs code for scripts/fsadm.sh?
>> If the answer is yes. I could share a suse special patch, this patch
>> had been run about 4 years in suse products.
> Hi
> If you have some patches provided with some good usable testing (lvm2 test suite)  - it could be possibly merged.

Patch for fsadm is already many years ago, but test suite is empty.
I plan to add some test cases then file the patch files.

> On the other hand helping/suggesting users to use Btrfs on top of lvm2 has also its logical 'question' marks.  Since  btrfs users should probably be avoiding placing 'another' layer between real hw - when btrfs should be mostly capable handling lvm2 features in its 'very own' way. Each layer has it's own measurable costs. And yeah we do not want to be involved into btrfs related recovery cases, as we simply never understood its handling of attached disks.

In my opinion, the using style of btrfs by many users are same as ext4/xfs.
btrfs has lots of features, but there are MAY experimental or not stable.
Users prefer to use btrfs core functionality. And not to speak of compatible
reasons, in many scenarios, btrfs still works with lvm or mdadm.

For minimal code design (minimal bug occur), in fsadm, we only treat btrfs as
another ext4/xfs style filesystem.
"fsadm resize" executes "btrfs resize"
"fsadm check" executes "btrfs scrub"


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