Journaling for a flaky FreeBSD VirtualBox guest.

[Nikos Vassiliadis]

On 28/2/2013 9:41 πμ, Alan Gutierrez wrote:
> I'm getting to know FreeBSD by running a 64-bit FreeBSD guest in a VirtualBox
> machine on my OS X Mountain Lion laptop. On occasion, when waking up from sleep,
> the FreeBSD virtual machine will not restart. VirtualBox marks it as "Aborted."

Maybe you should pause the guest before putting the host to sleep?

>
> When I restart FreeBSD, I've found on a number of occasions that the `.git`
> directory of the project I was working on when my laptop went to sleep has
> become corrupted. `git` won't recognize the directory. I try to rebuild the
> repository with `git fsck`, but it's usually broken. My `.zsh_history` file has
> been corrupted at restart, which I've recovered by removing the last line which
> contains binary nonsense.
>
> I run a Linux guest that suffers the same abuse, but does not lose data.
>
> My question:
>
> If anyone runs FreeBSD in VirtualBox, what VirtualBox settings do you use so
> that UFS will work correctly and recover recent writes?
>
> I'm using UFS built by the install media.
>
>   % mount
> /dev/ada0p2 on / (ufs, local, journaled soft-updates)
> devfs on /dev (devfs, local, multilabel)
>
> I'm using the disk and disk controller setup that VirtualBox suggested when when
> I told it I was building a FreeBSD machine. A single IDE drive on an IDE
> controller with "Use host I/O cache enabled." The VirtualBox documentation says
> that a virtual SATA controller is preferred if you choose to uncheck "Use host
> I/O cache enabled."
>
> http://www.virtualbox.org/manual/ch05.html#iocaching
>
> So...
>
>   * How should I configure my filesystem for maximum durability, since the
>   VirtualBox virtual drives appear to be flaky?

I think geom_journal will serve you better for this purpose. Geom
journal records everything, that is data and metadata changes.

I have used geom journal on my freebsd-current box and it has
stood tenths of kernel panics and a few power-offs without a
single failure.

I haven't researched about the type of controller or other settings
since it was never needed to. Occasional full fscks never revealed
corruption.

Just my 2 cents, HTH, Nikos