Re: [gentoo-user] Hard drive noise

[Rich Freeman]

On Sat, Dec 19, 2015 at 2:56 AM,  <covici@××××××××××.com> wrote:
>
> I was never able to get either zfs or btrfs to work correctly, zfs was
> very vulnerable -- I forgot to export a zfs on a usb drive and got an
> enless loop of processes untill I rebooted.  Btrfs never did work for
> me, I created a pool,  copied my root file system, usr and var into
> ssubvolumes, and copied my files, but when I would boot into it,
> everything was messed up, processes thought files were missing, very
> strange.  So, how did you set up either one of those -- I would love to
> use it because I have ssds and I don't want to rely on their firmware
> either.

Well, I don't have much personal experience with zfs, but the ZFS on
Linux lead is a Gentoo dev, so you're in good company there all the
same.  I personally use btrfs.

The obvious caveat is that it is still relatively experimental, and
raid5/6 is VERY experimental.  I plan to convert to raid5/6 at a
future date but am staying away from it for now (and a selling point
of btrfs is that reshaping in-place is easy).

I can't really vouch for what went wrong with your migration.  It
could be anything from a failure to preserve all your file attributes
to something with btrfs itself or your bootloader config/etc.  It
isn't hard to do a new install in btrfs though, and you can always
mess with it in a VM, or even mess with doing migrations in a VM.

My btrfs install notes are at:
https://docs.google.com/document/d/1VJlJyYLTZScta9a81xgKOIBjYsG3_VfxxmUSxG23Uxg/edit?usp=sharing
(I still plan to merge this stuff into the handbook.  Maybe a good
holiday project...  Oh, and if it isn't already obvious anybody can
add comments and half this list seems to have already done so.)

Oh, for a boot image I tend to use system rescue CD since it has all
the necessary userspace and is gentoo-based (and you can always emerge
--sync and install whatever you need inside it).  I tend to use the
alternate kernel since it is newer, and with btrfs newer tends to be
better.  In production I'm currently on 3.18 eyeing an upgrade to 4.1.
I tend to stay on the latest longterm, but not when they are first
declared as longterm.  That seems to be the sweet spot for getting
btrfs features and bugfixes, but not getting as many of the
regressions.  I use grub2/dracut to boot, and that is in my guide.

If you follow those notes for a stage3 install it should "just work."
If you want to mess around I suggest just doing a vanilla install on a
VM once to validate that it works for you and then tweak from a
position of strength.

-- 
Rich