Bug 1017159

Summary: Cannot use BTRFS partition as root when already used
Product: [Fedora] Fedora Reporter: Taylor Smock <smocktaylor>
Component: anacondaAssignee: Anaconda Maintenance Team <anaconda-maint-list>
Status: CLOSED NOTABUG QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: low Docs Contact:
Priority: unspecified    
Version: 20CC: amulhern, anaconda-maint-list, dshea, g.kaviyarasu, jonathan, mkolman, sbueno, smocktaylor, vanmeeuwen+fedora
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Hardware: Unspecified   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2013-10-09 17:48:08 UTC Type: Bug
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Description Taylor Smock 2013-10-09 10:57:11 UTC 
Description of problem:
When using a large BTRFS partition for multiple "virtual" partitions, Fedora cannot be installed to a subvolume (the installer does not give the option).


How reproducible:
Every time, once set up.

Steps to Reproduce:
1. Install Ubuntu with BTRFS (I have it under dm-crypt as well)
2. Add subvolumes (in my case, one for "data", one for "gentoo", one for "fedora". Ubuntu made "@home" and "@". "@" was renamed to "@ubuntu"
3. Attempt to install Fedora on the same BTRFS partition.

Actual results:
Installer wanted a "clean" root partition -- which is what the "fedora" subvolume was for.

Expected results:
Ability to select a subvolume for Fedora which is empty, or create a new subvolume for fedora when the root partition is BTRFS.

Additional info:
I do have Gentoo and Ubuntu on the same BTRFS partition -- the boot partitions are separate, so it should not be a limitation.
Comment 1 David Lehman 2013-10-09 17:20:48 UTC 
You should be able to create a new subvolume in your existing btrfs filesystem to install fedora to.

You'll want to use custom partitioning (review/modify/&c). Create a new btrfs device with mountpoint '/'. If necessary, select your existing btrfs filesystem/volume from the dropdown menu on the lower-left of the "configure mountpoint" area.

"Empty" or "fresh" filesystems that already exist are not supported for use as the root filesystem, but a new subvolume that we create is acceptable.
Comment 2 Taylor Smock 2013-10-09 17:48:08 UTC 
I figured it out (I was trying to specify a subvolume for the root filesystem, and was expecting the installer to do something like the following: 
    subvolume delete [name] ; subvolume create [name] 
instead of using Fedora's defaults, in order to avoid naming conflicts). I'll do what I did with Ubuntu, but it isn't always clear that "adding" a partition with BTRFS partitions will add a subvolume instead of wiping the entire partition.

Anyway,
Thanks.

Closing as NOTABUG. Because it isn't a bug.
Comment 3 David Lehman 2013-10-09 17:55:13 UTC 
Yeah, you're right -- it can be a bit of a guessing game as far as what exactly will happen behind the scenes. In general, though, we won't ever remove/destroy devices without you asking us to do so -- that's the worst kind of surprise. Thanks for the report.