BTRFS concerns (was: Re: Plan for tomorrow's FESCo meeting (2011-06-01))

Stephen John Smoogen smooge at
Thu Jun 2 17:47:36 UTC 2011

On Thu, Jun 2, 2011 at 11:44, Chris Adams <cmadams at> wrote:
> Once upon a time, Josef Bacik <josef at> said:
>> These sort of issues are my priority and I've spent the last 2 months
>> specifically working on the kvm performance differences between ext4
>> and btrfs.  Now we're not on par with ext4 yet, but we aren't 2-3
>> times slower any more, maybe at the most we're 20% slower.  Thanks,
> How does it compare to straight LVM for virtual images?  I create a big
> LV and then only use part of it for the host OS VG; when I create VMs, I
> create a VG for each (or I can snapshot an existing "base" VG).
> It is my understanding that one goal for btrfs is to take LVM out of the
> picture for the common case; i.e. btrfs can do its own logical volume
> management.  If that's the case, there needs to be something comparable
> to the VM-on-VG setup (in terms of ease-of-management and performance).

I wonder if the btrfs solution would be that you would just use raw
partitions and not use btrfs for it.

/dev/sda1 is /boot
/dev/sda2 is swap
/dev/sda3 is btrfs /
/dev/sda4 is VM-01
/dev/sda5 is VM-02

Stephen J Smoogen.
"The core skill of innovators is error recovery, not failure avoidance."
Randy Nelson, President of Pixar University.
"Let us be kind, one to another, for most of us are fighting a hard
battle." -- Ian MacLaren

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